Presidents, Congress, and the Use of Force
William Howell
Harvard University
Littauer Center #228
Cambridge, MA 02138
[email protected]
Jon Pevehouse
University of Wisconsin
110 North Hall; 1050 Bascom Mall
Madison, WI 53706
[email protected]
We thank the Center for American Political Studies at Harvard University and the Wisconsin
Alumni Research Foundation for financial support; and Kevin Warnke and Doug Kriner for
research assistance.
Debates over Congress’s involvement in foreign military engagements trace back at
least to the Republic’s founding. But irrespective of the normative issues at stake (e.g.,
should Congress shape foreign policy?), a basic point of fact remains unresolved: can
Congress effectively constrain presidents from unilaterally exercising force abroad? While
illustrative case studies abound, few empirical investigations systematically address the topic.
In principle, Congress should contribute to the politics surrounding the use of
military force. The Constitution vests Congress with the power to raise and support armies,
to provide and maintain a navy, and to regulate the military forces, all of which make
“Congress a major participant in foreign policy” (Fisher 1998: 178). Beyond their
enumerated powers, Congress can cut off a mission’s funding; its members can appeal to
public opinion; as they can kill other aspects of the president’s legislative agenda (Lindsay
and Ripley 1993: 22-35). While the president retains considerable discretion to use force
when (and as) he pleases, Congress can increase the marginal costs of foreign military
ventures. In many instances – e.g. when presidents face particularly controversial or risky
foreign conflicts – congressional support or opposition may prove decisive.
The existing empirical literature on the use of force, however, does not examine
whether presidents balance their “preference for action” (Ostrom and Job 1986: 544) against
Congress’s stated interests. While it demonstrates that elections, public opinion, and the
economy influence decisions to deploy U.S. military forces abroad, this literature regularly
ignores the influence of domestic political institutions. Rarely are any measures of
congressional relations with the president included in statistical models on the use of force;
and when included, they are crudely specified, typically nothing more than an indicator
variable for divided government (Gowa 1998; Fordham 2002).
1
We revisit the event-count models used to predict uses of force, adding appropriate
measures of congressional support for the president. Our findings are unambiguous, and
run directly against the notion that politics stop “at the water’s edge.” Between 1945 and
1995, partisan support within Congress serves as a significant predictor of the number of
foreign military engagements each quarter. Effects are especially large with regards to major
military initiatives and persist even when controlling for a host of other domestic and
international factors. As partisan support within Congress increases, presidents engage in
military initiatives more and more often; but as support within Congress wanes, so does the
frequency with which presidents exercise their authority to use military force abroad.
This paper proceeds a s follows. The first section reviews the empirical literature on
the use of force in the international relations subfield, and the theoretical literature on
presidential-congressional relations within the American politics subfield. The second
section applies these theoretical insights about executive-legislative relations to presidents’
decisions about whether to deploy military troops abroad. The third examines the empirical
relationship between the partisan composition of Congress and the number of uses of force
during the post-War era. The final section concludes.
Section I: The Relevant Literatures
There are, at present, two relevant literatures on the domestic politics of international
engagement. One is located within International Relations, the other within American
Politics. We consider each in turn.
The International Relations Literature
The use of U.S. armed forces as a political bargaining tool (such as the Berlin Airlift,
the Cuban Missile Crisis, and ongoing interventions into the Middle East and Central
2
America) represents one of the most potent expressions of executive authority. Not
coincidentally, the practice has garnered a large academic following, beginning with the
pioneering work of Barry Blechman and Stephen Kaplan in 1978. Blechman and Kaplan
were principally concerned with the international conditions (e.g., whether the Soviet Union
or China was a party to a crisis, whether troops were already deployed in the region, the
relative nuclear capabilities of the United States and the Soviet Union) that lead presidents to
initiate lower-level military ventures, what they termed “force without war.” Blechman and
Kaplan identified 226 such incidents between 1946 and 1976 and tracked when, and
whether, U.S. presidents achieved their strategic objectives.
Beginning in the mid 1980s, scholars built upon Blechman and Kaplan’s database to
test a confluence of international relations theories about inter-state conflict and political
psychology insights into executive decision-making. Cha rles Ostrom and Brian Job’s study
(1986) added an important set of domestic variables to the study of the use of force.
According to Ostrom and Job, U.S. presidents must create simple decision rules to balance
the competing demands of the presidency. As commander-in-chief, chief executive, and
“political leader,” presidents “monitor salient dimensions in the domestic, international, and
political arenas” before committing U.S. forces abroad. Domestic politics, however, retain
special significance. Indeed, in Ostrom and Job’s empirical analysis, the substantive impacts
of domestic variables (public aversion to war, a weighted economic misery index,
presidential approval, “overall presidential success,” and national elections) on the use of
force were consistently as strong if not stronger than their international counterparts (1986:
555).
The bulk of studies following Ostrom and Job have examined how the economy and
public opinion influence presidents’ decisions to deploy troops abroad. Patrick James and
John Oneal (1991) introduced a new variable that tapped international threats to U.S.
3
interests, yet still found that the same domestic political factors that Ostrom and Job
introduced were largely responsible for the use of force. Benjamin Fordham (1998)
subsequently argued that economic factors and public opinion do not directly shape
presidential decision-making, but instead influence how the president views his external
environment. The president, according to Fordham, only “sees” opportunities to use force
when the domestic economy is poor – when inflation is low and employment high,
presidents have few incentives to imperil their reelection prospects with risky foreign military
ventures.
Other scholars have lodged numerous methodological critiques of the use of force
literature. Meernik (1994) has argued that quantitative studies of the U.S. use of force suffer
from selection bias: there are myriad domestic and international contexts in which the U.S.
does not respond. By only examining actual uses of force, Meernik correctly pointed out,
scholars have assembled an incomplete view of the dynamics of presidential decisionmaking. More recently, Mitchell and Moore (2002) and Fordham (2002) have raised
important issues of data comparability (scholars use different years in analyzing their
hypotheses) and temporal dynamics (uses of force tend to be clustered together in time)
which may compromise previous statistical findings.
While much divides the protagonists in the use of force literature, one assumption is
consensual: Congress is weak.1 Indeed, an assumption of legislative impotence has achieved
the status of conventional wisdom:
The literature on U.S. foreign policymaking unambiguously demonstrates that
because of his constitutional prerogatives and political incentives as well as
congressional weaknesses in foreign policy, it is the president who exercises supreme
control over the nation’s military actions. (Meernik 1994: 122-3)
1
For an exception, see Richards and Morgan (1993).
4
Because the president is commander in chief of the military, Congress cannot (or will not)
try to constrain his freedom to pick battles, define the scope and duration of conflict, or set
the terms by which a conflict ultimately is resolved. While Congress may direct domestic
policymaking, its hold over foreign policy is quite tenuous; and when the president decides
to exercise military force abroad, members of Congress can only complain on Sunday
morning talk shows. For the most part, the president’s authority over military matters is
beyond repute.
Consider, by way of examples, the work on two of the causal mechanisms which
underlie the use of force literature: the diversionary war hypothesis and “rally around the
flag” effects. The diversionary war hypothesis suggests that heads of state deploy troops
abroad in an effort to distract attention away from poor economic indicators. Advocates of
the theory assume that Congress, the bureaucracy, and the public are blind to a leader’s true
intentions and, as a consequence, regularly accept on faith proffered justifications for
conflicts (for critiques, see Meernik and Waterman 1996; Blainey 1988; Levy 1989). By
sending troops abroad, it is supposed, presidents can shift public attention away from a
failing economy and rally widespread support, as members of Congress (very much including
the opposition party) naturally and automatically fall behind their Chief Executive.
Congress, again, is largely absent from most empirical tests for “rally around the
flag” effects (Mueller 1973; MacKuen 1983; Ostrom and Simon 1985; Wittkopf and
Dehaven 1987; Lian and Oneal 1993). Congress’s stance on military ventures conducted
abroad, it is assumed, does not mediate the size or direction of changes in the president’s
public approval ratings. While “aggressive foreign behavior [may be] a useful tool for
dealing with domestic political problems,” domestic political institutions do not hinder the
president’s ability to engage in aggressive foreign behavior (Morgan and Bickers 1992: 26).
Quite the contrary, members of Congress are just as susceptible to the rally phenomenon as
5
is the general public (Stoll 1987). As Barbara Hinckley argues, “The use of force shows the
clearest conventional pattern: presidents are active and Congress accedes to what the
presidents request. On these occasions both Congress and the public rally around the
President and the flag” (1994: 80).
We question the “unambiguous demonstration” that domestic political institutions
do not, or cannot, impede the presidential use of force. Under many circumstances,
Congress constrains the president, limiting the size, frequency, and duration of military
initiatives conducted abroad. This does not make the president an empty vessel responding
to the whims of Congress. The president clearly retains profound informational and tactical
advantages over Congress that make him the most powerful actor in U.S. foreign policy
(Moe and Howell 1999). Still, the president cannot easily and automatically dupe his political
opponents – especially when doing so entails putting American troops in harm’s way. To
strip away the institutional setting in which the president operates is to dismiss the
institutional politics associated with the use of military force.
The American Politics Literature
While the existing use of force literatures gesture toward congressional-presidential
politics (DeRouen 1995), the treatment consistently is fleeting. This is unfortunate given the
tremendous volume of research on executive-legislative relations within the American
politics subfield (see, e.g., Binder 1999; Jones 1994; Mayhew 1991; Peterson 1990; Bond and
Fleisher 2000; Krehbiel 1999). Scholars of American politics have developed ample theories
with strong micro foundations on interactions between the executive and legislative
branches. None of these theories is addressed in the extant use of force literature.
Within the American presidency sub-field, a burgeoning body of work examines
when presidents will unilaterally set public policy given that Congress and the courts may
6
subsequently undo his actions (Cooper 2002; Howell 2003; Mayer 2001). Using executive
orders, proclamations, memoranda, and administrative orders, presidents have managed to
impose a wide array of public policies that never would have survived the legislative process.
This work demonstrates that the president’s powers of unilateral action – which very much
encompass the option to deploy troops abroad – are critically defined by the capacity and
willingness of Congress to subsequently overturn him.
When large and unified majorities govern Congress, presidents rarely exercise their
unilateral powers. As shown elsewhere (Howell 2003), when strong majorities stand in
support, the president would do better to engage the legislative process and set policy with
firm legislative footings; and when such majorities stand in opposition, the president cannot
hope to unilaterally set any public policy of consequence without provoking a congressional
response. But when small and divided majorities govern Congress, presidents have
incentives to strike out on their own. In this sense, congressional strength marks
presidential weakness, and congressional weakness presidential strength. The outcome is
hardly accidental, for it is the checks that each institution places on the other that determines
the overall division of power.
With regards to the use of force, inter-institutional dynamics shift somewhat, as a
clear asymmetry defines the relationship between Congress and the president. While
members of Congress can punish the president for deploying troops abroad, they cannot
readily impel military action in the face of presidential resistance. As such, in this realm –
unlike policymaking generally, where Congress has the option of legislating when the
president refuses to issue a unilateral directive – Congress’s impact manifests itself
principally as a constraint on presidential power. Congressional opposition to the president,
as such, should depress the relative number of military initiatives conducted abroad.
7
Strangely, no one in American politics has systematically examined whether Congress
influences the frequency with which presidents exercise force abroad. Instead, American
politics scholars have offered up little more than case studies, some of which herald
Congress’s impotence in foreign affairs (e.g. Hinckley 1994; Weissman 1995), others which
note celebrated examples of Congress successfully blocking military campaigns (Lindsay and
Ripley 1993). But while ready-made theories on the institutional foundations of unilateral
powers are easily applied to president’s decision to use military force, the American politics
literature is devoid of empirical tests.
Rarely are the limits of one field’s treatment of a topic so perfectly complemented by
the strengths of another’s. While scholars of American politics have developed rich
institutional theories that delineate the conditions under which presidents exercise their
unilateral powers, uniformly they have overlooked the conditions under which presidents
deploy troops abroad. Meanwhile, international relations scholars have constructed
impressive datasets on the use of force, but the theories they test consistently overlook
interactions between Congress and the president. Indeed, the international relations
treatment of the use of force assumes away legislative constraints on presidential power –
just as American politics scholars remain captivated by them.
Section II: Theoretical Micro-foundations
As in unilateral policymaking, the relevance of Congress should vary according to its
partisan composition. Without enough seats in Congress, and enough discipline within its
ranks, the opposition party can do little to derail presidents’ decisions to use force abroad –
for as the international relations literature rightly insists, decisions regarding when and where
the military intervenes ultimately reside with the commander in chief. But when the
opposition party is unified and large, it can credibly threaten to punish presidents who
8
pursue misguided military ventures. Such punishments need not derail or even stall every
military initiative. On average, though, viable congressional opposition should decrease the
likelihood that presidents will exercise force abroad.
But why should the partisan composition of Congress affect the president’s
discretion to use force abroad? More specifically, why should members of the president’s
party be especially likely to back the president? And why should members of the opposition
party, all else equal, be predisposed to object? We offer three answers drawn from the
literature on presidential-congressional politics.
Shared Electoral Fortunes: Precisely because their electoral fortunes are linked to
the president, congressional members of the president’s party have a vested interest in the
president’s success – just as members of the opposition party do in his failure. If
presidential approval ratings increase when presidents exercise force abroad, as the rally
around the flag literature suggests (Mueller 1973; MacKuen 1983; Ostrom and Simon 1985;
Wittkopf and Dehaven 1987; Lian and Oneal 1993); and if high presidential approval ratings
boost members’ electoral prospects, as the literature on coattails suggests (Campbell and
Sumners 1990; Campbell 1986; Ferejohn and Calvert 1984); then, all else equal, members’
willingness to grant the president broad discretion to exercise force abroad should critically
depend upon his partisan identification. Presidential uses of force redound to the electoral
benefit of members of the president’s own party and, by implication, to the detriment of the
opposition party. As such, members of the president’s party, all else equal, ought to actively
support the president’s plans to exercise force abroad, as members of the opposition party
cautiously may oppose them.
Credibility of Signals: With regards to the use of force, as opposed to most
domestic policy matters, profound informational asymmetries define relations between
presidents and Congress (Schlesinger 1989). Presidents have at their disposal considerable
9
amounts of private information about developments abroad and their impacts on the
nation’s strategic interests. Further, Congress has few formal mechanisms for corroborating
this information. When a president makes a case for deploying troops abroad, Congress,
ultimately, must decide whether or not to take him at his word.
Whether, in fact, members of Congress accept a president’s justification for
intervening in foreign crises critically depends upon the distance between their respective
ideological orientations. A number of game theoretic models demonstrate that the
credibility of signals improves as political actors’ preferences converge (Crawford and Sober
1982; Lupia and McCubbins 1994). The first principle of Keith Krehbiel’s information
theory of congressional committees, for instance, states that “the more extreme are the
preferences of a committee specialist relative to preferences of a nonspecialist in the
legislature, the less informative is the committee” (1992: 81). When senders and receivers in
incomplete information games share a common world view, the signals conveyed are
especially informative. Conversely, as preferences diverge, signals are often indecipherable.
If the president is to make an effective case for deploying troops, members of
Congress must believe the information he transmits. Shared ideological orientations
facilitate belief. All else equal, presidents should garner trust from members of his party, and
suspicion from the opposition party. As his party grows in size and strength, therefore, the
president ought to benefit from greater legislative discretion (formal and otherwise) to
exercise force abroad.
Currying Presidential Favor: Presidents can do a number of things to shore up the
electoral prospects of members of Congress. By visiting their districts; appearing in their
television advertisements; or introducing them to potential funders; presidents can
significantly affect members’ electoral returns. Precisely because constituents pay more
attention to domestic than foreign policy matters when deciding how to vote, members of
10
Congress often have little to lose, and often much to gain, from actively supporting a
president interested in exercising force abroad.
Of course, presidents work on behalf of members of their own party. Republican
Senators rarely have anything to gain from currying the favor of Democratic presidents; as
Democratic Senators have little reason to go out of their way to support Republican
presidents. To the extent that broad grants of authority in foreign affairs helps members
remain in the president’s good graces, Republican [Democratic] Senators have cause to
support Republican [Democratic] presidents when they consider exercising force abroad.
While resting upon different first principles, all of these micro-theories generate the
same prediction: Senate members of the president’s party will line up behind the president
during times of international crisis. But from a logistical standpoint, presidents can deploy
the military without first securing congressional approval. Indeed, an ability to strike first
and place upon Congress the onus of coordinating a response stands as a defining
characteristic of the president’s unilateral powers (Howell 2003). Why, then, should
presidents care about whether or not Congress supports a military use of force? How
exactly does opposition within Congress constrain the president ex ante? And why must
presidents anticipate the strength and source of this opposition, and adjust their military
plans accordingly? Again, several plausible explanations arise.
Dismantling the President’s Military Venture: Anticipating a large contingent
within Congress actively resisting their policies, presidents may be reticent to initiate force.
The opposition party within Congress may attempt to dismantle a particularly controversial
military campaign, refusing to appropriate needed funds, calling for the return of troops sent
on ill-conceived foreign missions, or raising concerns about the efficacy of the intervention.
Congress can actively work against the president, materially affecting the course of a military
campaign. In their study of the War Powers Act, David Auerswald and Peter Cowhey (1997:
11
523) show that Congress regularly places upon presidents obligations (reporting
requirements, budgetary limitations, accounting procedures) that can prove quite
burdensome. Having to stave off a mobilized opposition party within Congress during the
course of a military campaign may dissuade presidents from initiating force at all.
Coalescing Public Opinion: Congress exerts influence over public opinion
concerning foreign policy (Lindsay 1992: 3). Whether the issue is defense programs or
specific military operations, Congress can “take to the streets,” frame the ensuing debate,
and, with varying success, turn public opinion against the president’s preferred foreign policy
(H. Smith 1988; Caldwell 1991). If the president anticipates that Congress will push public
opinion against him, with regard to the use of force specifically, or against his approval
ratings more generally, he may be less likely to engage in the use of force.
Dispelling Myths of Political Resolve: A large body of work on crisis bargaining
shows that when negotiating with one another, states have strong incentives to conceal their
true private preferences (Morrow 1986); further, an inability to credibly reveal these
preferences can lead to the breakdown of negotiations and the initiation of war (Fearon
1994). Kenneth Schultz, however, has shown that the existence of an opposition party
(which has no incentive “to collude in a bluff”) makes signals sent between states more
informative, and hence mitigates the likelihood of military conflict. When Congress
supports the president, the president can credibly convey his intentions to follow through on
a military venture; but when Congress opposes the president, the president will have a much
more difficult time signaling his resolve. “The opposition party can undermine the
credibility of some challenges by publicly opposing them. Since this strategy threatens to
increase the probability of resistance from the rival state, it forces the government to be
more selective about making threat” – and, concomitantly, more cautious about actually
using force (1998: 840). The potential for domestic political strife, as such, creates a
12
disincentive for the president: it weakens the credibility of signals of resolve, thereby
encouraging bargaining intransigence on the part of rival states. The resulting (higher)
likelihood of protracted conflict and its increased cost will lead the president to be wary of
such strategies (Smith 1998).2
There are, then, a variety of reasons why members of the president’s party should be
more likely to support the president, reasons that trace back to their shared electoral
fortunes, the credibility of signals conveyed across the branches of government, and the
electoral benefits of currying the president’s favor. So too are there multiple reasons why
presidents will anticipate congressional opposition and, possibly, disband planned military
ventures, foremost among them being Congress’s ability to directly challenge the president
and the associated problems of credibly conveying strong resolve to rival states. The
empirical tests that follow do not allow us to evaluate these competing micro-theories, and
hence we remain agnostic as to their individual merits. Instead, we test the basic expectation
that arises out of all these micro-theories: the partisan composition of Congress should
systematically influence the frequency with which presidents exercise force abroad.
Section III: Empirical Tests
To test whether congressional politics play a role in the president’s calculus to deploy
military troops abroad, we conduct several statistical examinations of the United State’s use
of force between 1945 and 1995. Our data draw from Fordham (1998a), Fordham and
2
Schultz (2001) builds upon this selection logic, arguing that empirical tests for audience costs are likely to
systematically underestimate those costs to state leaders.
13
Sarver (2001), and Zelikow (1987), all of which update the original Blechman and Kaplan
time series that ended in 1976.3
Blechman and Kaplan ranked demonstrations of force on a five point severity scale.
Many scholars use only the most severe uses of force in their analyses, i.e. instances that
involved the deployment of nuclear capabilities or the mobilization of multiple aircraft
carrier task groups, battalion, or combat wings (e.g., Fordham 1998a, 1998b). This decision,
however, is by no means universal (see Mitchell and Moore 2002). Rather than make
exclusionary decisions in our own analyses, we initially take three cuts of the force data: all
uses, major uses (1-3 on the severity scale), and minor uses (4-5). A priori, one might expect
Congress to exert the most influence in major uses of force, but we do not want to dismiss
the possibility of broader legislative involvement in foreign policy. To this end, we present
results using all three versions of the dependent variable.
Figure 1 shows the historical trends of the use of force in U.S. foreign policy.4 Note
that there is a general increase in the use of force during the Cold War era, with two major
peaks in the early 1960s and mid-1980s. The first peak reflects increased pre-Vietnam War
activity in Southeast Asia, multiple crises in the Middle East, as well as the recurrent Berlin
crises of the early Kennedy Administration. The 1980s peak largely represents U.S.
deployments to the Middle East after the Israeli invasion of Lebanon and increased activity
in Central America.
To measure congressional support for the president, we compute the percentage of
seats held by the president’s party in the Senate and label this variable Percent President Party.
We focus on the Senate because of its greater involvement in foreign policy matters;
Ironically, the one article that focuses at length on presidential-congressional relations uses the Militarized
Interstate Dispute data (MIDS) rather than the traditional use of force data (Gowa 1999). Given the MIDS
underreporting of threats to use force, the Blechman/Kaplan data are superior to test theories of U.S. foreign
policy. See Fordham and Sarver 2001.
4 Yearly data is used in the graphs simply for purposes of visual coherence. All analyses use quarterly data.
3
14
measures that incorporate the House, however, generate comparable, and occasionally
stronger, results. Presumably, as the size of the president’s party increases within the Senate,
the president should enjoy additional discretion to deploy troops abroad. Conversely, as the
opposition party increases in size, the president’s ability to use military force should
attenuate.5
Data are aggregated on a quarterly basis. For the major force time series,
autocorrelation function plots do not reveal any dynamics, making standard event count
models appropriate. A slight dampening dynamic process, however, is observed for the
minor and all force time series. Simple event count models, in these instances, may yield
inefficient and potentially biased results. Both Poisson autoregressive (PAR) models and
general estimation equations (GEE) models allow for corrections of AR processes in time
series event count data (Brandt and Williams 2001; Zorn 2000). In this context, the principal
difference between these classes of models concerns the structure of the autoregressive
process. PAR models isolate and correct for AR processes across an entire time series; GEE
models correct for AR processes within clusters of observations. Ultimately, the choice
between models is inconsequential, as all yield virtually identical results. For the sake of
consistency, therefore, we report for each of the use of force measures Poisson regressions
with robust standard errors that account for clustering on each president.6
To account for individual differences in each president’s leadership style, military
experience, and policy agendas, all of which may have some bearing on his willingness to
5
We also compute an alternative to the Percent President Party variable based on the “legislative potential for
policy change” (LPPC) scores created by Cooper, Brady, and Hurley (1977). These scores use (1) the size of
the majority party; (2) the majority party’s internal cohesiveness; (3) the size of the minority party; and (4) its
cohesiveness. We modify the scores only slightly, substituting the president’s and opposition parties for the
majority and minority parties respectively. This measure generates nearly identical results across all models. In
addition, we also estimated models that include a simple indicator variable for divided government. Estimates
that are consistent with those reported below arise regardless of whether divided government is defined on the
basis of only the Senate majority party or the majority party in both chambers of Congress.
6
The ACF plots and results from PAR and GEE models are available from the authors upon request.
Likelihood-ratio tests for each model confirm the appropriateness of Poisson over negative binomial models.
15
exercise force, we include intercept variables for each administration. 7 The use of force,
then, is assumed to be a function of the partisan composition of Congress and presidential
fixed-effects.
(1)
FORCE = α + β 1PresidentParty + β iPresident + ε
If our expectations about the relevance of Congress hold, β 1 should be positive and
statistically significant.
The first three columns of Table 2 present the estimated Poisson regression results
on all, minor, and major uses of forces. For two configurations of the dependent variable,
congressional-presidential politics do not seem to play a strong role. When using all and
only minor uses of force as the dependent variable, Percent President Party is not statistically
significant. Major uses of force, however, are affected by domestic political factors, as the
partisan composition of the Senate appears to play a significant role in shaping the
president’s willingness to deploy troops abroad. The positive coefficients suggest that as the
size of the president’s party grows, the president’s freedom to use the military for significant
purposes also increases.
Although theory suggests that the size of the president’s party affects the ability of
the president to use force abroad, it is largely silent with regard to the functional form of the
relationship. Upon reflection, however, there is good reason to expect that the impact of
Percent President Party will be non-linear. Given supermajoritarian procedures and the powers
and privileges associated with becoming the majority party in Congress, increasing the size of
the president’s party from 49 percent to 51 percent or from 59 to 61 percent is likely to be
more important than an increase from 39 to 41 (Krehbiel 1999). To test for the possibility
7
F-tests regularly reject the null that the presidential fixed effects are jointly insignificant.
16
of non-linear effects, we add a quadratic term to Model 1 and re-estimate the impacts for
each version of the dependent variable.
The results are presented in columns 4-6 in Table 2. For the non-linear model
estimations, results are now consistent across each version of dependent variable. In all
three estimates, the size of the president’s party has a strong impact on the propensity of the
U.S. to use force. The signs of the linear and quadratic term suggest a U-shaped functional
form. Marginal increases in party strength at the low end of the distribution leads to a slight
decline in the use of force; but for marginal party gains at the middle and upper ends of the
distribution, the propensity to use force increases more dramatically. For example, given the
estimates in column 6, a move from 45 percent to 48 percent for the President’s party yields
an increase of 6 percent in the expected total number of uses of force, yet a move from 55 to
58 percent leads to an increase of over 19 percent in the expected count. These predicted
effects continue to grow as one increases the size of the president’s party: beginning with 60
percent, a gain of seats resulting in a 63 percent majority produces a 26 percent increase in
the expected frequency of conflict.
Based upon the estimates in columns 4-6 of Table 3, Figure 2 provides three sets of
predicted incident rates. Each graph in Figure 2 is created through the use of statistical
simulations (see King, Tomz, and Wittenberg 2000). The vertical lines represent 95 percent
confidence intervals around each point prediction.
The first panel illustrates the predicted number of major uses of force for different
values of Percent President Party. Although the shape of the relationship is quadratic, the
influence of seat gains is quite small below the fifty percent mark; thereafter, the slope
increases markedly. For all and minor uses of force, there is a steeper decline in propensity
to use force for values at the lower end of the spectrum. These differences, however, are
small compared to the relative impact of seat gains above the fifty percent threshold. In
17
each case, the minima of predicted values for uses of force lie between 45 and 50 percent.
As the president’s party approaches a majority, his freedom of action expands, while gains
above and beyond 50 percent yield ever increasing executive autonomy. The substantive
meaning of these results is unambiguous: the level of partisan support for the president
within the Senate stands out as a major determinant of the U.S. propensity to use force
abroad.
As discussed in section 2, scholars have focused almost exclusively on other
domestic and international factors that shape the president’s ability to use force abroad. In
order to ensure our findings are not the result of omitted variable bias, we estimate the
following model which incorporates many of the alternative hypothesized influences on the
use of force:
(2)
FORCE = α + β 1PresidentParty +β 2PresidentParty2 + β 3Unemployment +
β 4CPI + β 5Approval + β 6W-Elect + β 7P-Elect + β 8War + β 9ColdWar +
β 10Hegemony + β 11WorldDispute + β iPresident + ε
Again, we interchange three measures of FORCE (all, minor, and major) as the dependent
variable. Consistent with a burgeoning literature on the political economy of the use of
force (Ostrom and Job 1986; Fordham 1998a), we incorporate the quarterly unemployment
rate and the inflation rate (CPI), both of which were taken from the Bureau of Labor
Statistics. Past research finds that poor economic performance is likely to lead to incentives
for the president to act aggressively in foreign policy affairs (James and Oneal 1991;
Fordham 2002).
Because much of the literature on the use of force draws upon theories of
diversionary war, we control for the president’s public approval rating. The impetus for
much of the original quantitative work on the subject was Ostrom and Job’s (1986) finding
that approval ratings were a highly significant determinant of the use of force – though
18
subsequent research has proven less definitive on the matter. We measure the first Gallup
approval rating for the president in each quarter. 8
A related body of work examines whether elections usher in additional uses of force
(Stoll 1984; Gaubatz 1991). This research contends that “rally around the flag” effects
establish incentives for presidents to use force during the months immediately preceding an
election, provided that the nation is not already at war. Thus, we introduce two variables,
W-Elect and P-Elect. The first is coded “1” during the first three quarters of a presidential
election year in which the U.S. is involved in a major war; the second is coded “1” in the first
three quarters of the remaining peace-time presidential election years.
The next four variables capture facets of the international environment that may
impinge on the president’s autonomy in foreign policy. Due to contemporary military
commitments, there should be a tendency for presidents to employ force for bargaining
purposes less often during times of war. Thus, we create a dummy variable labeled “War”,
coded “1” during periods of international wars in which the U.S. was involved (here, Korea,
Vietnam, and the Gulf War). The Cold War was also a period of unprecedented concern
over international engagement of U.S. forces. To control for its influence on the U.S.
propensity to use force, we include a dummy variable coded “1” during the 1945-1989
period.
To account for systemic forces that have been linked to the onset of both interstate
wars and disputes (Mansfield 1994; Mansfield and Pevehouse 2000), we include a measure of
U.S. hegemony during the period of analysis. The measure is the percentage of international
military capabilities held by the United States and derives from the Correlates of War
Some research, including Ostrom and Job, do not measure approval at the outset of the period of
observation, but throughout the period. This specification invites endogeneity problems, as rally around the
flag effects emanating from exercises of force may have popularity ratings. In the handful of quarters missing
approval data, we fill the data by using a linear interpolation. We also interpolated by using the last known poll.
The results are consistent regardless of the method used.
8
19
Capabilities data set (Small and Singer 1990). Finally, we include a measure of the number of
world military conflicts which begin in each quarter of observation. Presumably, a higher
number of world conflicts provides more opportunities for the U.S. to respond with the use
of force (Meernik 1994; Fordham 1998a). The data is taken by aggregating non-U.S.
militarized interstate disputes (MIDS) over the period of observation.9 As in table 2, all
models include presidential fixed effects and are estimated using Poisson regressions with
robust standard errors.
Table 3 presents estimates across the three measures of force. Consistent with our
initial findings, the linear and quadratic terms measuring senatorial support for the president
are highly significant predictors of the quarterly number of the use of force regardless of the
form of the dependent variable. The distinction between major and minor uses of force,
then, appears less important when the influence of Congress is examined. While the
marginal effects of senatorial support on the predicted uses of force differ slightly for minor
and major uses of force at the lower end of the distribution, on the whole, the effects appear
robust. For all three versions of the dependent variable, the linear and quadratic terms
generate consistent and significant effects. Similar to the effect of party size on major uses
of force in Model 1, increases at lower levels of party size (45 percent to 48 percent) yield
smaller increases (roughly 6 percent), than to corresponding increases at higher levels of
party size (moving from 55 percent to 58 percent brings an increase in 18 percent in
expected count).10
Many of the remaining model estimates also are consistent with previous findings,
although some of these congruencies disappear when only major uses of force are evaluated.
The MIDS data ends in 1992. To extend the data until 1995, we performed a comprehensive search for
events that seemingly met the MIDS criteria from 1992-1995. For a description of the MIDS data, see Jones,
Bremer, and Singer 1996.
10
Figures are based on estimates in column 3 of Table 3.
9
20
Specifically, estimates for the economic variables (Unemployment and CPI) mirror the
original Ostrom and Job findings that higher levels of “economic misery” correspond with
higher levels of military activity (these are also consistent with Fordham 1998a, b). For
example, increasing the level of inflation by one standard deviation leads to an increase of 28
percent in the expected count of all uses of force. Yet, when only major uses of force are
evaluated, these results weaken significantly. In fact, in the model of major uses of force, the
influence of all economic-related variables disappears entirely.
The elections variables yield some findings that diverge from previous studies. Some
scholars do not differentiate war-time and peace-time elections (Ostrom and Job 1986;
Gowa 1998; Meernik 1994). Interestingly, none of those studies finds elections to be
significantly related to the use of force. Fordham, who does differentiate elections, finds
that war-time elections are significant predictors of the use of major force.11 The models in
table 3 indicate that it is peace-time elections that matter, but only with regard to minor uses
of force. In these minor force models, the expected count difference increases over 30
percent during peace-time elections. One possible explanation could be that while
presidents may want to gain support for foreign policy during an election year, they are
unwilling to take large risks to do so and thus confine their activities to military operations
involving a single squadron or company of troops.
The approval variable never attains statistical significance in any of our estimations,
even when including alternative specifications that are not reported here. This is consistent
with the findings of both Meernik and Fordham, but counters Ostrom and Job’s claim that
lagging approval ratings establish incentives for presidents to use force. Other variables are
of the predicted sign – the Cold War has a positive and statistically significant influence on
Fordham’s election variables differ from ours. While we isolate the three quarters leading up to the national
election, Fordham 1998a isolates all four quarters in the calendar year of an election, as well as the first quarter
of the following year when an incumbent is re-elected.
11
21
military activities. Based on the estimates of column 3, the expected number of uses of force
more than doubles during the Cold War. Other control variables, such a hegemony and ongoing wars depress the propensity of presidents to deploy U.S. troops, yet their statistical
significance varies based on the dependent variable. The level of military hostility in the
world appears to have no consistent or statistically significant influence on the propensity of
the U.S. to engage the military.12
Given these results, we contend that much of the previous empirical work on the use
of force in U.S. foreign policy suffers from omitted variable bias. Without taking account of
presidential-congressional politics, as well as fixed presidential effects, both of which clearly
impact the use of force, scholars risk excluding a significant determinant of U.S. foreign
policy. Moreover, these findings intimate something more fundamental about much of the
theory that spawned the literature on U.S. use of force policy – namely, that the same forces
that affect prospects for the president’s legislative agenda also determine the discretion of
presidents to exercise force abroad.
Domestic and Foreign Policy Tradeoffs
Increased resources devoted to one policymaking sphere may imply decreased
resources available for another. When embroiled in military conflicts abroad, presidents
have considerably less time to direct their domestic legislative agenda through Congress;
conversely, when freed from foreign military entanglements, presidents can assist an
increasing number of laws along the legislative path. If true, we should find evidence of a
trade-off between foreign and domestic politics. All else equal, presidents who spend an
exorbitant amount of time on domestic policy should be less engaged in foreign military
12
Because the use of force data contains some overlapping uses of force (different operations during the
same calendar period against the same target), we re-estimated all models removing the overlapping
observations. The resulting estimations are nearly identical to those presented here.
22
ventures; meanwhile, presidents who stake their legacies on military initiatives should fail to
enact large numbers of significant laws.
To test this claim, we add one independent variable to equation 2: the number of
“non-trivial” laws enacted each quarter. Non-trivial laws encompass all “landmark,”
“important,” and “ordinary” laws enacted each Congress. Landmark enactments consist of
the “Sweep One” laws identified in David Mayhew’s Divided We Govern (1991). By
measuring the amount of coverage laws received in the New York Times, the Washington Post,
and the annual Congressional Quarterly almanacs, Howell et al (2000) categorized all of the
remaining laws as important, ordinary, or trivial. Between 1945 and 1995, 17,830 total laws
were enacted, 1 percent of which were deemed landmark, 1 percent important, 10 percent
ordinary, and 87 percent trivial.13
We focus exclusively on uses of major force, which demand from presidents more
attention and resource commitments. These demands should intensify the trade-off
between domestic and international policies, leading to a negative correlation between the
passage of non-trivial laws and the use of force. The first column of table 4 presents the
results. The number of non-trivial laws enacted each quarter has a positive and statistically
significant relationship with the number of uses of force – exactly the opposite of what one
would expect given a theory positing a tradeoff between domestic and international politics
in presidential decision-making.14 Moreover, Percent President Party retains its sign and
statistical significance.
13
Howell et al 2000 used these count data to test the hypothesis that Congress enacts fewer important laws
during periods of unified than divided government. They find that while divided government depressed the
number of landmark laws enacted, it has no effect on the number of important and ordinary enactments, and
has a positive effect on the number of trivial laws passed each Congress between 1945 and 1994. For the
analyses conducted for this paper, the time series is updated through 1995.
14
The impacts of Percent President Party on all and minor uses of force are statistically insignificant.
23
This model lends no support for the notion that presidents must choose between
foreign and domestic policy initiatives. Quite the contrary, increased legislative activity
seems to imply greater freedom for presidents to exercise military force abroad. An
institutional theory of presidential-congressional relations helps explain why. When the
president enjoys strong support in Congress, he is less constrained in both foreign and
domestic policy. Stronger congressional support leads to a comparatively easier road for the
president to pursue his legislative agenda, just as it affords greater discretion to send troops
abroad. Tradeoffs between domestic and foreign policy should be less [more] acute when
the president enjoys strong [little] support in Congress. The very institutional structures that
support the enactment of numerous laws – namely, widespread support within Congress for
the president – also lend the chief executive considerable discretion to exercise force abroad.
As a further test of this conjecture, we estimate a set of Seemingly-Unrelated Poisson
models, with the use of major force and enactment of significant laws as the two dependent
variables.15 As with the use of force, our theory does not anticipate the functional form the
relationship between presidential strength and the passage of laws will take. Thus, one set of
estimates (table 4, column 2) contains only a linear term of Percentage President Party, while the
other set (table 4, column 3) contains both a linear and quadratic term. Even when
controlling for the correlated error terms across equations, congressional support for the
president is statistically significant, although its functional form differs. In column 3, neither
the linear nor the quadratic measure of Presidential power is significant, yet alone, the linear
term is highly signifi cant. Larger values for Percentage President Party lead to the enactment of
more non-trivial laws and the initiation of increased numbers of military ventures.
Congressional support or opposition for the president appears to significantly impact
domestic and foreign policy.
15
As in all previous models, both the Force and Laws equations include presidential fixed-effects.
24
Relations between Congress and the president have immediate consequences for
both the lawmaking process and the commitment of American troops abroad. The same
underlying forces that facilitate lawmaking also lend presidents greater autonomy to use
military force. While trade-offs between domestic and foreign policy may exist at the
margins, their influence appears to be overwhelmed by the institutional foundations of
executive-legislative relations.
Section IV: Conclusion
For too long, the use of force literature has ignored domestic political institutions.
Indeed, most research equates domestic politics with election cycles, public opinion, and the
state of the economy, and nothing more. Finding that presidential public approval ratings
are unrelated to the use of force between 1953 and 1978, Moore and Lanoue offer the
sweeping conclusion that “international politics, not domestic politics, [must be] the primary
determinant of conflictual U.S. foreign policy behavior” (forthcoming). Because it is not an
integral component of the domestic politics of international engagement, Congress,
presumably, does not need accounting for.
We argue otherwise and show empirically that Congress is a key determinant in the
president’s proclivity to use force. On the whole, we find a strong, non-linear correlation
between the composition of Congress and the frequency with which presidents use force
abroad. This relationship holds for all use of force time series, though the effects are
clearest with regards to major deployments. As their party’s share of the Senate increases,
presidents conduct military campaigns abroad with increasing frequency. Conversely, as the
size of the opposition party increases, presidents act with force less and less often.
This finding is robust across various model specifications and using multiple
operationalizations of congressional support. Moreover, our findings cast doubt on the
25
conjecture that presidents face a zero-sum tradeoff between foreign and domestic politics.
Quite the contrary, the same factors that facilitate the passage of the domestic agenda will
facilitate the use of force as well. The larger the support of the president in the Senate, the
more likely are major uses of force and more likely is the passage of important pieces of
legislation. Further, it appears that many of the prior conclusions regarding the influence of
public opinion, elections, and the state of the economy may suffer from omitted variable
bias.
For scholars, the proper question should not be whether domestic political
institutions, on the whole, matter. Rather, the challenge is to specify exactly when they
matter, exactly how their constraining influence manifests, and what this entails for the
ultimate conduct of American foreign relations. In future research, scholars would do well
to study the particular causal mechanisms that allow Congress to influence foreign policy.
Moreover, these mechanisms may influence the choice of foreign crises presidents respond
to, the timing, scope, and duration of the response, and the terms of the conflict’s ultimate
resolution.
This paper establishes a preliminary point of departure. While the president certainly
commands considerable discretion to exercise force when, and as, he pleases, Congress
remains a force to be reckoned with. In the conduct of foreign military relations, as in most
every other area of public policy, Congress often wields significant influence over
presidential decision-making.
26
(A) Major Uses of Force per Year
(B) Minor Uses of Force per Year
8
14
12
6
10
8
4
6
4
2
2
0
0
1945
1955
1965
1975
1985
1995
1975
1985
1995
1945
1955
1965
1975
1985
1995
(C) All Uses of Force per Year
22
20
18
16
14
12
10
8
6
4
2
0
1945
1955
1965
Figure 1: U.S. Use of Force, 1945-1995
NOTE: Graphs use annual counts and present a non-linear smoother for visual coherence.
27
(A) Influence of Presidental Party Support on Major Uses of Force
(B) Influence of Presidental Party Support on Minor Uses of Force
Expected Minor Uses of Force
Expected Major Uses of Force
3
2
1
0
3
2
1
0
0.350
0.500
Proportion of Seats in President's Party
0.600 0.625
0.350
0.500
Proportion of Seats in President's Party
0.600 0.625
(C) Influence of Presidental Party Support on All Uses of Force
Expected All Uses of Force
5
4
3
2
1
0
0.350
0.500
Proportion of Seats in President's Party
0.600 0.625
Figure 2: Predicted Force Counts
Note: Vertical Lines are 95% confidence intervals, based on simulations
28
Table 1. Descriptive Statistics.
Variable
Dependent Variables
Major Force
Minor Force
All Force
Independent Variables
Pct. President Party in Senate
CPI
Unemployment
Approval
Election Year (War)
Election Year (Peace)
War
Cold War
Hegemony
Non-trivial Laws Passed
Mean
Std Dev.
Min.
0.7
1.2
1.9
0.9
1.2
1.5
0
0
0
0.52
4.4
5.6
54.9
0.06
0.12
0.26
0.88
0.34
12.2
0.09
3.7
1.7
13.7
0.24
0.32
0.44
0.32
0.06
11.3
0.35
-2.7
1.1
23.0
0
0
0
0
0.26
0
Max.
5
5
7
0.68
18.9
10.7
87.0
1
1
1
1
0.52
56
N = 204 for each variable
29
Table 2. Poisson Estimates of Uses of Force by the United States: 1945-1995.
All Force
Minor
Major
Percent President Party
0.473
(2.796)
-1.179
(3.928)
2.717**
(1.212)
(Percent President Party) 2
--.--
--.--
Constant
0.629
(1.497)
204
N=
All Force
Minor
Major
-32.072***
(6.661)
-42.380*** -18.704**
(9.424)
(7.747)
--.--
34.318***
(8.563)
43.094*** 22.813***
(12.016)
(8.439)
1.087
(2.086)
-1.643**
(0.656)
8.120***
(1.128)
204
204
204
10.685*** 3.213*
(1.672)
(1.732)
204
204
** = p < .01; * = p< .05; one-tailed tests.
Note: Each model is estimated using Poisson regression with Huber/White/sandwich clustered standard
errors. Each model also contains fixed effect terms for each Presidential administration, which are not
reported to conserve space.
30
Table 3. Poisson Estimates of Use of Force by the United States: 1945-1995.
All Force
Percent President Party
Minor
Major
-26.948***
(2.021)
-34.951***
(6.380)
-18.270*
(10.184)
(Percent President Party) 2
30.306***
(2.546)
37.564***
(7.532)
22.228**
(11.306)
Unemployment
0.152***
(0.036)
0.170***
(0.046)
0.119
(0.089)
CPI
0.054**
(0.025)
0.067***
(0.022)
0.027
(0.040)
Approval
-0.0004
(0.007)
0.001
(0.008)
-0.004
(0.008)
War-time Election
0.127
(0.229)
-0.010
(0.303)
0.401
(0.264)
Peace-time Election
0.287**
(0.119)
0.425***
(0.067)
-0.038
(0.271)
Ongoing War
-0.501***
(0.177)
-0.587***
(0.186)
-0.377
(0.256)
Cold War
0.477***
(0.069)
0.152*
(0.090)
0.794***
(0.142)
Hegemony
-2.912*
(1.625)
-4.453*
(2.376)
-0.334
(3.236)
World Disputes
-0.004
(0.020)
0.011
(0.034)
-0.023
(0.025)
Constant
6.321***
(0.859)
8.211***
(1.689)
2.771
(2.559)
N=
204
204
204
*** = p < .01; ** = p < .05; * = p< .10; two-tailed tests.
Note: Each model is estimated using Poisson regression with Huber/White/sandwich clustered
standard errors. Each model also contains fixed effect terms for each Presidential administration,
which are not reported to conserve space.
31
Table 4. Poisson Estimates of Use of Force Controlling for Legislative Activity: 1945-95.
MAJOR FORCE
____
DV: USE OF FORCE
Percent President Party
-17.723*
(10.545)
-18.270*
(10.184)
-18.270*
(10.184)
(Percent President Party) 2
21.546*
(12.086)
22.228**
(11.306)
22.228**
(11.306)
Unemployment
0.111
(0.072)
0.119
(0.089)
0.119
(0.089)
CPI
0.030
(0.036)
0.027
(0.040)
0.027
(0.040)
Approval
-0.001
(0.007)
-0.004
(0.008)
-0.004
(0.008)
War-time Election
0.461**
(0.223)
0.401
(0.264)
0.401
(0.264)
Peace-time Election
-0.007
(0.312)
-0.038
(0.271)
-0.038
(0.271)
Ongoing War
-0.517*
(0.302)
-0.377
(0.256)
-0.377
(-0.256)
Cold War
0.798***
(0.118)
0.794***
(0.142)
0.794***
(0.142)
Hegemony
-0.750
(2.896)
-0.334
(3.236)
-0.334
(3.236)
World Disputes
-0.024
(0.027)
-0.023
(0.025)
-0.023
(0.025)
Laws Passed
0.020**
(0.008)
--.--
--.--
Constant
2.584
(2.347)
2.771
(2.559)
2.771
(2.559)
Percent President Party
--.--
1.274**
(0.592)
-9.006
(7.344)
(Percent President Party) 2
--.--
--.--
10.813
(8.161)
Approval
--.--
-0.007
(0.005)
-0.008
(0.006)
DV: LAWS PASSED
32
Table 4 (con’t)
MAJOR FORCE
DV: LAWS PASSED (con’t)
War-time Election
--.--
-0.109
(0.112)
-0.072
(0.140)
Peace-time Election
--.--
-0.144
(0.228)
-0.150
(0.234)
Ongoing War
--.--
0.250
(0.161)
0.267
(0.175)
1.589***
(0.375)
4.033**
(1.831)
204
204
Constant
N=
204
*** = p < .01; ** = p< .05; * = p < .1; two-tailed tests.
Note: Each model is estimated using Poisson regression with Huber/White/sandwich clustered standard errors. Each model
also contains fixed effect terms for each Presidential administration, which are not reported to conserve space.
33
REFERENCES
Auerswald, David and Peter Cowhey. 1997. “Ballotbox Diplomacy: The War Powers
Resolution and the Use of Force.” International Studies Quarterly 41 (3): 505-528.
Binder, Sarah. 1999. "The Dynamics of Legislative Gridlock, 1947-96." American Political
Science Review. 93(3): 519-34.
Blainey, Geoffrey. 1988. Causes of War. 3 rd ed. New York: Free Press.
Blechman, Barry and Stephen Kaplan. 1978. Force Without War: U.S. Armed Forces as a
Political Instrument. Washington DC: Brookings.
Bond, Jon and Richard Fleisher . 2000. Polarized Politics: Congress and the President in a Partisan
era. Washington DC: CQ Press.
Brady, D., J. Cooper and P. Hurley. 1979. “The Decline of Party in the U.S. House of
Representatives: 1886-1968.” Legislative Studies Quarterly 10: 381-407.
Caldwell, Dan. 1991. The Dynamics of Domestic Politics and Arms Control. Columbia: Univ. or
South Carolina Press.
Campbell, James E. 1986. “Presidential Coattails and Midterm Losses in State Legislative
Elections.” The American Political Science Review. 80(1): 45-63.
Campbell, James E. and Joe A. Sumners, 1990. “Presidential Coattails in Senate Elections.”
The American Political Science Review. 84(2): 513-524.
Cooper, Philip. 2002. By Order of the President. Lawrence, KS: University Press of Kansas.
Crawford, Vincent and Joel Sobel. 1982. “Strategic Information Transmission.” Econometrica .
50: 1431-51.
DeRouen, Karl. 1995. “The Indirect Link: Politics, the Economy, and the Use of Force.”
Journal of Conflict Resolution 39 (4): 671-695.
Fearon, James D. 1994. “Domestic Political Audiences and the Escalation of International
Disputes.” The American Political Science Review. 88: 577-92.
Ferejohn, John A. and Randall L. Calvert. 1984. “Presidential Coattails in Historical
Perspective.” American Journal of Political Science. 28(1): 127-146.
Fisher, Louis. 1998. The Politics of Shared Power: Congress and the Executive. College Station,
Texas: Texas A&M University Press.
Fordham, Benjamin and Christopher Sarver. 2001. “Militarized Interstate Disputes and
United States Uses of Force.” International Studies Quarterly 45: 455-66.
Fordham, Benjamin. 1998a. “The Politics of Threat Perception and the Use of Force: A
Political Economy Model of U.S. Uses of Force, 1949-1994.” International Studies
Quarterly 42: 567-590.
Fordham, Benjamin. 1998b. “Partisanship, Macroeconomic Policy, and U.S. Uses of Force,
1949-1994.” Journal of Conflict Resolution 42 (4): 418-439.
Fordham, Benjamin. 2002. “Another Look at ‘Parties, Voters, and the Use of Force
Abroad’”. Journal of Conflict Resolution 46 (4): 572-96.
Freedman, L. and E. Karsh. 1993. The Gulf Conflict, 1990-1991: Diplomacy and War in the New
World Order. Princeton: Princeton University Press.
Gaubatz, Kurt. 1991. “Election Cycles and War.” Journal of Conflict Resolution 35: 212-44.
Gowa, Joanne. 1998. “Politics at the Water’s Edge: Parties, Voters and the Use of Force
Abroad.” International Organization 52 (2): 307-24.
Hall, David K. 1978. “The Laotian War of 1962 and the Indo-Pakistani War of 1971”. In
Force Without War, ed. Blechman and Kaplan. Wasington DC: Brookings Press.
Hinckley, Barbara. 1994. Less Than Meets the Eye: Foreign Policy Making the Myth of the Assertive
Congress. Chicago: University of Chicago Press.
34
Howell, William, Scott Adler, Charles Cameron and Charles Riemann. 2000. “Divided
Government and the Legislative Productivity of Congress, 1945-1994.” Legislative
Studies Quarterly.
Howell, William G. 2003. Power without Persuasion: A Theory of Direct Presidential Action.
Princeton: Princeton University Press.
James, Patrick and John R. Oneal. 1991. “The Influence of Domestic and International
Politics on the President’s Use of Force.” Journal of Conflict Resolution 35 (2): 307-32.
Jones, Charles. 1994. Presidency in a Separated System. Washington DC: Brookings Institution.
Jones, Daniel, Stuart Bremer, and J. David Singer. 1996. “Militarized Interstate Disputes,
1816-19902: Rationale, Coding Rules, and Empirical Patterns.” Conflict Management
and Peace Science. 15(2): 163-213.
Krehbiel, Keith. 1999. Pivotal Politics. University of Chicago Press.
Levy, Jack. 1989. “The Diversionary Theory of War: A Critique.” In Handbook of War
Studies, ed. Midlarsky. London: Unwin-Hyman.
Lian, Brian and John R. Oneal. 1993. “Presidents, the Use of Military Force and Public
Opinion.” Journal of Conflict Resolution 37 (2): 277-300.
Lindsay, James. 1992-3. “Congress and Foreign Policy: Why the Hill Matters.” Political
Science Quarterly 107: 607-28.
Lindsay, James and Randall Ripley. 1993. “How Congress Influences Foreign and Defense
Policy.” In Congress Resurgent: Foreign and Defense Policy on Capitol Hill, ed. Ripley and
Lindsay. Ann Arbor: University of Michigan Press.
Lupia, Arthur and Mathew McCubbins. 1994. “Who Controls? Information and the
Structure of Legislative Decision Making.” Legislative Studies Quarterly. 19(3): 361-84.
MacKuen, Michael. 1983. “Political Drama, Economic Conditions, and the Dynamics of
Presidential Popularity.” American Journal of Political Science. 27: 165-192.
Mansfield, Edward D. 1994. Power, Trade, and War. Princeton: Princeton University Press.
Mansfield, Edward D. and Jon Pevehouse. 2000. “Trade Blocs, Trade Flows, and
International Conflict”. International Organization 54 (4): 775-808.
Mayer, Kenneth. 2001. With the Stroke of a Pen. Princeton: Princeton University Press.
Mayhew, David. 1991. Divided We Govern. New Haven: Yale University Press.
Meernik, James and Peter Waterman. 1996. “The Myth of the Diversionary Use of Force
by American Presidents.” Political Research Quarterly 49 (3): 573-90.
Meernik, James. 1994. “Presidential Decision Making and the Political Use of Force.”
International Studies Quarterly 38: 121-138.
Mitchell, Sarah M. and Will Moore. 2002. “Presidential Uses of Force During the Cold
War: Aggregation, Truncation, and Temporal Dynamics” American Journal of Political
Science 46 (2): 438-453.
Moe, Terry and William Howell. 1999. “The Presidential Power of Unilateral Action.”
Journal of Law, Economics, and Organization 15 (1): 132-179.
Morrow, James. 1986. “A Spatial Model of International Conflict.” American Political Science
Review 80 (December): 1131-50.
Moore, Will and David Lanoue. “Domestic Politics and U.S. Foreign Policy: A Study of cold
War Conflict Behavior.” Journal of Politics, forthcoming.
Mueller, John. 1973. War, Presidents, and Public Opinion. New York: Wiley Press.
Ostrom, Charles and Brian Job. 1986. “The President and the Political Use of Force.”
American Political Science Review 80 (2): 541-66.
Ostrom, Charles and Dennis Simon. 1985. “Promise and Performance: A Dynamic Model of
Presidential Popularity.” American Political Science Review. 79: 334-358.
35
Peterson, Mark. 1990. Legislating Together: The WhiteHouse and Capital Hill from Eisenhower to
Reagan. Cambridge: Harvard University Press.
Schultz, Kenneth. 1998. “Domestic Opposition and Signaling in International Crises.” The
American Political Science Review. 92(4): 829-44.
Schultz, Kenneth. 2001. “Looking for Audience Costs.” Journal of Conflict Resolution 45 (1):
32-60.
Small, Melvin and J. David Singer. 1990. National Material Capabilities Database. ICPSR
Study No. 9903. Distributor: ICPSR, Ann Arbor, University of Michigan.
Smith, Alastair. 1998. “International Crises and Domestic Politics.” American Political Science
Review 92: 623-38.
Smith, Hedrick. 1988. The Power Game: How Washington Works. New York: Random House.
Stoll, Richard. 1984. “The Guns of November: Presidential Reelections and the Use of
Force, 1947-1982.” Journal of Conflict Resolution 28 (2): 231-46.
Waltz, Kenneth. 1979. Theory of International Politics. New York: McGraw Hill.
Weisman, Stephen. 1995. A Culture of Deference: Congress’s Failure of Leadership in Foreign Policy.
New York: Basic Books.
Wittkopf, Eugene and Mark Dehaven. 1987. “Soviet Behavior, Presidential Popularity, and
the Penetration of Open Political Systems.” In Charles Hermann, Charles Kegley,
and James Rosenau (eds.), New Directions in the Study of Foreign Policy. Boston:
Unwin Hyman.
Zelikow, P. D. 1987. “The United States and the Use of Force: A Historical Summary.” In
Democracy, Strategy, and Vietnam, ed. G. Osborn, et al. Lexington, MA: Lexington
Books.
36