States frequently employ overt and covert foreign-imposed regime change (FIRC) to pursue their foreign policy interests. Yet there is little scholarship on the question of whether FIRCs improve relations between the states involved. In fact, most FIRCs either fail to reduce—or increase—the likelihood of militarized disputes between interveners and targets. Fundamentally, FIRC entails a principal-agent problem: foreign-imposed leaders rule over states with interests different from those of the intervener. Whereas the intervening state wants the new leader to pursue policies that reflect its interests, once in power, such leaders are focused on ensuring their political survival, a task that is often undermined by implementing the intervener's agenda. Foreign-imposed leaders who carry out the intervener's desired policies attract the ire of domestic actors. These domestic opponents can force the regime to reverse course or may even remove it from power in favor of leaders who are hostile to the intervener; in both cases, the result can be renewed conflict with the intervener. Rwanda's replacement of Mobutu Sese Seko with Laurent-Désiré Kabila in Zaire illustrates this problem.

Is military intervention effective in spreading democracy? Existing studies disagree. Optimists point to successful cases, such as the transformation of West Germany and Japan into consolidated democracies after World War II. Pessimists view these successes as outliers from a broader pattern of failure typified by cases such as Iraq and Afghanistan. Those in between agree that, in general, democratic military intervention has little liberalizing effect in target states, but contend that democracies can induce democratization when they explicitly pursue this objective and invest substantial effort and resources. Existing studies, however, often employ overly broad definitions of intervention, fail to grapple with possible selection effects in countries where democracies choose to intervene, and stress interveners' actions while neglecting conditions in targets. Astatistical examination of seventy instances of foreign-imposed regime change (FIRC) in the twentieth century shows that implementing prodemocratic institutional reforms, such as sponsoring elections, is not enough to induce democratization; interveners will meet with little success unless conditions in the target state—in the form of high levels of economic development and societal homogeneity, and previous experience with representative governance—are favorable to democracy. Given that prospective regime change operations are likely to target regimes in poor, diverse countries, policymakers should scale back their expectations that democracy will flourish after FIRC.

Proponents of the selection effects argument claim that because democratic leaders run a higher risk of losing office than autocratic leaders if they fail to win wars, they are more careful than their authoritarian counterparts in choosing which wars to initiate. The robust marketplace of ideas in democracies also weeds out self-serving or ill-conceived policies and allows democratic leaders to better estimate the chances of victory. Democracies, according to this logic, tend to pick on weak or vulnerable opponents and thus win a disproportionate number of the wars they start. Both quantitative and qualitative evidence, however, challenges this conclusion. The statistical correlation between democracy and victory is not robust to reasonable alternative choices for analyzing the data. In particular, including draws as a war outcome renders statistically insignificant the finding that democratic initiators and targets are more likely to win. In addition, democratic leaders who initiate wars should be optimistic that they will win, but process tracing of the decision by Lyndon Johnson's administration to escalate the Vietnam War (one of these omitted draws) reveals that top officials knew at the time that escalation promised a costly, protracted stalemate, yet they chose to fight anyway. Moreover, domestic politics, if anything, contributed to Johnson's decision to fight in Vietnam despite the poor odds of victory because he believed that pulling out would spark a backlash and destroy his Great Society legislative program. The results of this combined analysis raise doubts about the democracy and victory thesis, and should prompt interest in other explanatory variables for military effectiveness.

Despite normative and legal injunctions against targeting civilians in war, as well as doubts regarding the effectiveness of such strategies, belligerents have frequently turned their guns on noncombatants. Two variables—desperation to win and to save lives on one's own side in protracted wars of attrition, and the intention to conquer and annex enemy territory—explain this repeated resort to civilian targeting. According to the desperation logic, costly and prolonged wars of attrition cause states to become increasingly anxious to prevail and to reduce their losses. Adopting a policy of civilian victimization permits states to continue the war while managing their losses and hopefully coercing the adversary to quit. In the appetite for conquest model, by contrast, belligerents specifically intend to seize and annex territory. Attackers in this model employ civilian victimization to eliminate enemy civilians, who can threaten the aggressor's immediate military position and present a future threat of rebellion. Multivariate analysis of interstate wars between 1816 and 2003 corroborates the importance of these factors,and a case study of the British starvation blockade of Germany in World War I supports the plausibility of the desperation mechanism.