The final three chapters examine the three primary substantive areas that affect U.S. foreign policy today: national security, global economic relations, and transnational issues. This chapter begins by reviewing national security and defense policy. While the concept of national security encapsulates military, economic, political, societal, and environmental security, the focus here is on defense policy. No other domain attracts more media attention, budgetary resources, and time commitments by political actors than the development and implementation of policies on national security and defense. At the same time, no other policy domain is as controversial to the public, both at home and abroad. Although the United States is commonly referred to as a peaceful country, it nonetheless averages 1.7 military actions per year. In 2014, the United States spent more on national defense than nearly all other countries in the world combined. The grand strategies and tactics of U.S. national security policies also have implications for the lives of U.S. soldiers, the U.S. public, and the international community. Thus, the importance attached to this foreign policy domain cannot be understated.

The concept of national security policy refers to how, when, and where the United States engages in the defense of territory, population, and natural resources. Grand strategy, which generally changes to some degree with each president, focuses on long-term statements and planning regarding the role the United States plays in global politics, its national interests, and the means or tactics for achieving those interests. Geopolitical assets, strategic culture, state-society relations, and structural factors all affect U.S. grand strategy. Modern examples include George W. Bush’s doctrine of primacy and preemption along with Clinton’s global engagement strategy, as well as Obama’s recognition of the limits of the U.S. world power.

Actors making U.S. security policy have a variety of planning options. Military intervention is often not the first choice; instead policy actors try coercive diplomacy, or threats against offensive actors in an attempt to influence behavior. With the exception of the Cuban missile crisis, coercive diplomacy often fails due to the domestic and international constraints facing U.S. policy makers. More often, the United States must choose whether to intervene preemptively or preventively. The decision to invade Iraq in 2003 proved to be complex, as the Bush administration argued it was a preemptive strike whereas critics argued that U.S. intelligence failures and the lack of military and offensive capabilities by Iraq made the invasion a preventive war.

The difficulties of making U.S. security policy have shifted from a focus on nuclear issues, such as mutual assured destruction (MAD) and the development of nuclear capabilities by additional countries, to a focus on a more destructive form of suicide terrorism. Terrorism continues to present new challenges to U.S. primacy in security policy based on the difficulties of asymmetric warfare and policing the homeland. This chapter discusses the tumultuous history of the United States’ efforts to combat asymmetric warfare at home and abroad and explores the nature of terrorism such as its definition, psychological effects, and religious claims. The chapter concludes by noting that the best countermeasures for combating terrorism are not to be found at the point of a gun, but rather in reason, dialogue, and a search for common understanding amongst peoples.