"There is an ongoing debate about the effects of U.S. military presence on conflict around the globe. In one view, U.S. military presence helps to deter adversaries, restrain U.S. partners from adopting provocative policies, and make it easier for the United States to achieve its aims without the use of force. In another view, U.S. military presence tends to provoke adversaries and encourage allies to adopt more reckless policies, and it increases the likelihood that the United States will be involved in combat. The authors of this report analyze historical data to assess how U.S. military presence -- in particular, U.S. troop presence and military assistance -- is associated with the interstate and intrastate conflict behavior of states and nonstate actors. Troop presence and military assistance have different effects. Stationing U.S. troops abroad may help deter interstate war. A large U.S. regional troop presence may reduce the likelihood of interstate conflict in two ways: by deterring potential U.S. adversaries from initiating interstate wars or by restraining U.S. allies from initiating militarized behavior. However, U.S. military presence may increase interstate militarized activities short of war. U.S. adversaries may be more likely to initiate militarized disputes against states with a larger U.S. in-country troop presence. U.S. troop presence does not appear to reduce the risk of intrastate conflict or affect the level of state repression. U.S. military assistance is not associated with changes in interstate conflict behavior. However, provision of U.S. military assistance may be associated with increased state repression and incidence of civil war. These findings have implications for near-term decisionmaking on U.S. forward troop presence in Europe and Asia."--Publisher's description

Five specialists examine the historical relationship of culture and conflict in various regional societies. The authors use Adda B. Bozeman's theories on conflict and culture as the basis for their analyses of the causes, nature, and conduct of war and conflict in the Soviet Union, the Middle East, Sinic Asia (China, Japan, and Vietnam), Latin America, and Africa. Drs. Blank, Lawrence Grinter, Karl P. Magyar, Lewis B. Ware, and Bynum E. Weathers conclude that non-Western cultures and societies do not reject war but look at violence and conflict as a normal and legitimate aspect of sociopolitical behavior.

Using an original data set of 145 ground, air, and naval interventions from 1898 through 2016, this report identifies those factors that have made U.S. military interventions more or less successful at achieving their political objectives. While these objectives were often successfully achieved, about 63 percent of the time overall, levels of success have been declining over time as the United States has pursued increasingly ambitious objectives. The research combines statistical analysis and detailed case studies of three types of interventions -- combat, stability operations, and deterrence. The research highlights that the factors that promote the successful achievement of political objectives vary by the nature of the objective and the intervention. For example, sending additional ground forces may help to defeat adversaries in combat missions but may have a more contingent effect on success in institution-building in stability operations, where nonmilitary resources and pre-intervention planning may be especially vital. The report offers five main policy recommendations. First, planners should carefully match political objectives to strategy because factors that promote success vary substantially by objective type. Second, sending more forces does not always promote success, but for certain types of objectives and interventions, greater capabilities may be essential. Third, policymakers should have realistic expectations regarding the possibility of achieving highly ambitious objectives. Fourth, pre-intervention planning is crucial. Finally, policymakers should carefully evaluate the role that might be played by third parties, which is often under appreciated.

Accompanying CD-ROM contains graphic footage of various war wound surgeries.

This report analyzes trends in violent conflict and their implications for defense planning. It presents models estimating levels of conflict to 2040 under different scenarios and suggests early warning indicators of potential increases in conflict.

This report provides empirical evidence on the deterrent effects of U.S. overseas military forces. It also offers guidance about how the deterrent effects of forces may vary by their type, size, and location.

This report identifies several important trends that are shaping regional security. It examines traditional security concerns, such as energy security and the proliferation of weapons of mass destruction, as well as newer challenges posed by political reform, economic reform, civil-military relations, leadership change, and the information revolution. The report concludes by identifying the implications of these trends for U.S. foreign policy.

Why is it so difficult for a great power or a hegemon to retrench its overseas military power? Specifically, why are U.S. military bases and troops still largely where they were five years ago, twenty years ago, or even seventy years ago? Through developing a theory of great-power persistence, this book offers an explanation. Closely aligned with neoclassical realism, the theory argues that the murkiness of the anarchic international system combines with specific psychological inclinations of individuals to produce “better-safe-than-sorry” policies. In the United States, decisions on troop deployments are powerfully influenced by the broader foreign-policy community. Its members tend to be risk-averse and highly sensitive to the possibility that even minor troop withdrawals might set off harmful geopolitical chain reactions. Preferring the status quo over any uncertain alternative, they want their country to continue to maximize its influence and project its military power abroad in order to steady wobbling geopolitical “dominoes.” The theory is put to the empirical test through a systematic analysis of U.S. overseas troop deployments, withdrawal attempts, and retrenchment resistance during the presidency of Donald Trump, which represents an ideal test case for these mechanisms. Even if U.S. voters elected a retrenchment advocate as president, and despite that the United States is a gradually declining power, the period saw very little change in U.S. overseas troop deployments. The book concludes that, barring any dramatic, unforeseeable international event, the vast network of overseas U.S. military bases and troops is likely to persist for a long time to come.

This book suggests a new explanation for why international peace interventions often fail to reach their full potential. Based on several years of ethnographic research in conflict zones around the world, it demonstrates that everyday elements - such as the expatriates' social habits and usual approaches to understanding their areas of operation - strongly influence peacebuilding effectiveness. Individuals from all over the world and all walks of life share numerous practices, habits, and narratives when they serve as interveners in conflict zones. These common attitudes and actions enable foreign peacebuilders to function in the field, but they also result in unintended consequences that thwart international efforts. Certain expatriates follow alternative modes of thinking and acting, often with notable results, but they remain in the minority. Through an in-depth analysis of the interveners' everyday life and work, this book proposes innovative ways to better help host populations build a sustainable peace.