a foreign power’s costs of obtaining an enforceable agreement, strong domestic opposition will decrease the expected costs of regime change. This is because politically weak leaders are not just more resolved to resist; they are also often easier to overthrow. As long as the stronger state can find an opposition group willing to collaborate, the more powerful that group, the more it can assist the foreign power in toppling the leader, thereby reducing the costs of regime change to the foreign power. This opposition need not be the same as the one causing the leader’s resistance. A leader, for example, might refuse the foreign power’s demands in order to defend against an internal rival, while the foreign power uses external opposition to impose regime change.
In what follows, I first address how domestic opposition, whether internal or external, affects the foreign power’s estimates of regime-change costs and why foreign powers can often find opposition groups willing to collaborate. I end with a discussion of how major events or crises can serve as catalysts for regime change by prompting policymakers to reassess the costs of using military force.
THE STRENGTH OF THE DOMESTIC OPPOSITION
A domestic opposition’s power depends primarily on two attributes—the extent of its military capabilities and the size and unity of its political following. Opposition groups with military capabilities can lower the costs of removing their nation’s leader in a variety of ways. First, they can conduct military operations and absorb casualties, thus reducing the number of troops that the foreign power must contribute to a military invasion. In 1852, Brazil looked to partner with local actors to overthrow Argentinean dictator Juan Manuel de Rosas. Knowing it could not overthrow Rosas on its own, Brazil instead aligned with the politically ambitious Argentinean governor of Entre Ríos, Justo José de Urquiza. It was Urquiza’s army of twenty thousand, assisted by a much smaller number of Brazilians and Uruguayans, that ultimately defeated Rosas.43 Even when relatively small in number, opposition fighters can still contribute militarily to a foreign power’s invasion by conducting sabotage operations, providing intelligence, harassing enemy troops, and generating propaganda to hasten a military victory. Both Nazi Germany and the Soviet Union built their informal empires by relying on pro-Nazi and pro-Soviet domestic opposition groups that served as a fifth column.44
Opposition groups that represent a former ruling faction often have a ready-made group of supporters willing to fight for them. During the nineteenth and early twentieth centuries, liberal and conservative regimes in Central America intervened repeatedly in neighboring states to restore their ideological allies to power.45 Between 1855 and 1907, Honduras experienced regime change seven times as liberal and conservative leaders in both Guatemala and Nicaragua assisted Honduran liberals and conservatives in seizing power.
Opposition to the leader can also be latent. In these instances, widespread opposition may exist, but the majority of the population is too intimidated to organize and fight. Foreign powers may have to contribute greater military aid to mobilize latent opposition, but they may still judge the costs of regime change as low because the population is unlikely to rally to the leader’s defense. Foreign powers may also anticipate (rightly or wrongly) that their invasions will inspire the latent opposition to fight. Uganda’s Idi Amin faced latent opposition as a result of his regime’s brutality. When Tanzanian troops invaded in 1978 to topple Amin, liberated civilians, encouraged by the arrival of foreign forces, joined the fight.46 Unpopular leaders may also attempt to ward off coups by conducting purges that strip the military of its talent and resources. This may leave the military unable to fend off a foreign invader and thereby lower the foreign power’s anticipated costs of an invasion. Amin’s purges and abuses had led to such low morale among Ugandan troops that many were reportedly more interested in looting or fleeing than fighting off the Tanzanian invasion.47
The stronger state can also use dissident groups to reassure the target population that it does not have imperial designs. When Vietnam invaded Cambodia in 1978, it sought to assuage long-standing Cambodian fears of Vietnamese domination by cobbling together the Kampuchean United Front for National Salvation (KUFNS) from pro-Hanoi Communists and Khmer Rouge defectors. Although the KUFNS’s military contribution was small, Vietnamese leaders saw the group as a way to win broad Cambodian support.48 The foreign power may also reduce its diplomatic and reputational costs by using domestic opposition groups to legitimize its regime-change operation to an international audience. Tanzanian president Julius Nyerere, for example, looked to dodge international criticism of Tanzania’s invasion of Uganda by using exiles to take control of Kampala.49
Foreign powers may also use indirect or covert force to avoid the military and political costs of direct military force. They may, for example, use economic pressure or covert propaganda campaigns to weaken the leader politically and encourage a coup; or, they may supply rebels with military aid, assistance, and training. In 1949, President Harry Truman’s administration attempted to overthrow the Communist government of Albania by covertly training, funding, and transporting Albanian exiles and Albanian Americans to that country’s shores.50 In 1957, the Eisenhower administration began covertly funding Indonesian rebels to take down President Sukarno, whose government it feared would fall prey to communist influence.51
Foreign powers can also avoid using direct military force by encouraging the internal opposition, which operates within the government, to undertake a coup. The internal opposition has access to military and political power, which it can use to oust the leader. The United States, for example, overthrew the Iranian prime minister, Mohammad Mosaddeq, in 1953 without the use of military force. Foreign economic pressure and domestic political violence had sapped Mosaddeq’s once strong domestic support. With his political position weakened, the CIA was able to orchestrate a coup by organizing protests, bribing high-ranking army officials, and pressuring Mohammad Reza Shah to collaborate.52 External opposition groups that manage to gain influence may also be able to launch coups. The Communist Party of Czechoslovakia, for example, acquired control over the army, police, and key ministries after performing well in the 1946 elections. When it began losing support in 1948, Moscow urged the party to orchestrate a takeover by purging noncommunists from the security forces and ministries under its control. When noncommunist government ministers resigned in protest, the party staged demonstrations. Fearing the Soviets would use the unrest as a pretext for intervention, the noncommunist president, Edvard Beneš, ceded to the communists’ demands, allowing for their complete takeover.53
In some instances, foreign powers may accomplish regime change simply by convincing the target state’s military not to fight. In 1909, for example, the United States supported Nicaraguan rebels in their attempt to overthrow the populist president José Santos Zelaya. When the rebels proved unable to defeat the Nicaraguan army, the United States stationed marines between the two sides, supposedly as a neutral force to protect Americans. The US commander then forbade the Nicaraguan army from firing in the direction of the rebels. The Nicaraguan army stood by, helpless, as the United States continued supplying the rebels with weapons and funds.54 Once Zelaya realized a military victory was impossible, he offered to step down.
Over the long term, opposition groups with either popular support or military capabilities may also require less foreign aid to survive if they do attain power. When the opposition has a large following, the population is less likely to question its right to rule, which may spare the foreign power from having to help prop it up. This is often the case when foreign powers reinstall popularly supported governments, much as the Allies did in Nazi-occupied countries following World War II. Alternatively, when opposition groups lack a large following but possess significant military capabilities, they often use those capabilities to eliminate their opponents. In Chile, for example, the United States helped facilitate a military coup in 1973, after which the military used its monopoly on the use of force to violently suppress dissent.55
In choosing regime change, the foreign power must also consider whether the opposition shares its policy preferences. This requirement, however, is often easily met, as opposition groups may willingly compromise their policy positions to attain foreign
