Leaders facing little opposition will not necessarily yield to all of the foreign power’s demands. Their willingness to concede depends not only on their political vulnerability but also on their military and economic weakness. Leaders with the resources to resist a foreign power’s pressure may refuse concessions even though the political costs of conceding are low. Politically strong leaders may also avoid concessions they fear could create opposition. These leaders can often afford to take a firmer bargaining position because they know that the foreign power has no credible threat to replace them. Nevertheless, when compared to leaders who have similar resources, but face staunch domestic threats, leaders without domestic opposition should be more willing to make concessions. The threat to their political survival is much lower. Domestically weak leaders, in contrast, will require greater incentive to accept settlement terms that increase their political vulnerability. For scholars, then, the issue becomes determining the conditions under which the foreign power will give a politically weak leader sufficient incentive to accept an agreement.
The Foreign Power’s Costs of a Settlement
To attain a favorable settlement, first the stronger state must convince the targeted leader to accept its terms; second, it must convince the leader to uphold them. The first task requires the stronger state to incur coercion costs, while the second entails enforcement costs. In this section, I detail both sets of costs, showing how each is influenced by the domestic threat the targeted leader faces.
THE COSTS OF COERCION
To convince a targeted leader facing domestic opposition to accept a settlement that could be politically costly, the foreign power must first demonstrate that it poses a greater threat than the leader’s domestic threat.23 Simply possessing greater military capabilities is not enough. The foreign power must also convince the target it will follow through on its threats. This could be difficult to do, especially if the foreign power has interests that span the globe. If the issue at stake is outside its core security interests, its target might well doubt the foreign power’s willingness to sacrifice significant resources in a less important arena.24 In the rationalist literature on war, such doubts drive what is known as the incomplete-information problem.25 When actors cannot judge their opponents’ capabilities or resolve, they often resist at the bargaining table, believing they can do so with impunity. Although each side could theoretically communicate its resolve and capabilities, neither has reason to trust the other since each has incentive to bluff. Targeted leaders that believe their domestic enemies are more resolved to challenge them than their foreign ones may, therefore, resist a foreign power’s demands to protect their political positions.
One way to overcome an incomplete-information problem is with a costly signal, which entails actions a less committed actor would avoid.26 Whereas a bluffer might make a verbal threat to go to war, only truly resolved ones will bear the costs of actually preparing for it. Costly signals can also include verbal threats for which policymakers would incur political costs if they failed to follow through. But preparing for war has an additional benefit that verbal threats do not: war preparation measures increase the chances of military victory.27 A state that mobilizes a large invasion force, for example, is far more likely to achieve a military victory than one that does not. Likewise, states that form military alliances or attempt to weaken their targets with military or economic pressure are more likely to prove victorious than ones that simply threaten war. Thus, the size and scope of the foreign power’s war-preparation measures, more so than mere verbal threats, can convince a targeted leader of the foreign power’s resolve to fight. Consequently, they can also influence which enemy—the foreign or domestic one—the targeted leader sees as more dangerous.
Mobilizing for war may not be enough to convince some leaders to concede. They might be facing such deadly domestic threats that they would rather risk a fight with the foreign power. They may hope to hold out in a protracted conflict or, like Reza Shah discussed earlier, settle for terms that allow them to save face. Though such targets may be difficult to intimidate, agreements are often still possible. The state demanding concessions can use limited force to weaken the target’s defenses, resolve, or both. Bombing or economic blockades can be used to deny the target the means to hold out or to weaken its resolve.28 The foreign power can also target the leader’s supporters, imperiling their interests to ensure they see compliance as necessary.29 The stronger state can also use positive incentives, such as offers of aid or security guarantees, to make compliance more appealing, or it can soften its terms to attain its core aims. It can also use scorched-earth tactics to make resistance very costly for the target or defeat the target militarily, leaving it no choice but to accept a settlement.30 Of course, some targets may possess such powerful military capabilities or resolve that they cannot be defeated. But if the foreign power can defeat the target and impose regime change, then it should be able to convince the target to accept a settlement as long as that settlement offers the leader the chance to remain in power.
The problem with obtaining a bargaining agreement, however, is that policymakers may not want to bear the costs necessary to secure them. Whether the stronger state uses a costly signal to convince the target to concede, uses force to wear down the adversary’s will or ability to resist, or uses positive incentives to induce concessions, agreements can be costly for the side seeking change. Costly signals, for example, must be costly to the state making the threat to be effective.31 Targeted leaders understand that a less resolved adversary will tolerate moderately costly signals to achieve its aims at the bargaining table. Thus, in order to convince the target to back down, the state making the threat must mobilize a large army or take some other costly action to prove its determination to win at all costs.32 The same holds for the use of limited force and the offer of positive inducements. The more resolved the target is to remain in power, the more is required to obtain the target’s concessions.
The expense of an agreement typically goes beyond monetary costs. These expenses can also include political, diplomatic, opportunity, humanitarian, reputational, and military costs. Mobilizing an army, for example, could generate diplomatic costs by alienating the stronger state’s allies. For example, Vietnam’s relations with China deteriorated after Vietnam responded militarily to Cambodia’s border incursions in 1977.33 War-preparation measures could also prove unpopular at home.34 The fear of incurring domestic political costs kept both the Reagan and George H. W. Bush administrations from publicly threatening to use military force in Panama to oust Noriega.35 Maintaining foreign bases, allies, and weapons systems to ensure a credible military threat against a foreign leader can create opportunity costs by drawing resources away from domestic priorities or from deterring other foreign threats. Bombing campaigns or sanctions can also entail costs. The 1998 NATO bombing campaign in Kosovo, for example, created diplomatic costs by aggravating US-Russia relations at a time when the two countries were reconciling.36 Sanctions and bombing campaigns that generate high civilian casualties can also create reputational costs, as the foreign power comes to be seen as the aggressor. States may attempt to avoid these costs by restricting the kinds of sanctions they use or the types of targets they bomb. But these efforts usually undermine the coercive threat by convincing the opponent that the foreign power’s resolve