ABSTRACT
The United States is at or nearing one of its periodic crossroads in its national security orientation toward the world, and while it is certainly possible to overinflate its impact or ultimate effects, there is a marked change in the contemporary debate. Since 1945, the United States has been the leading power in the world, the country whose policies and actions have mattered everywhere. Much of this predominance has had a national security base, premised on and often enforced by the military strength of the United States, which has been the major measure of national security. During this period, the United States has generally adopted an expansive, sometimes aggressive global role based on an abundance of resources that could be devoted to national security chores.
Often, the result has been outcomes that have favored American interests in the world, but occasionally they have not. American diligence held the line in Korea during the 1950s (the division of the Korean peninsula into two countries that the North Koreans sought to erase) and prevailed in the Cold War competition with the Soviet Union and its allies at the end of the 1980s. The outcomes in places like Vietnam, Iraq, and Afghanistan, however, were not unambiguously positive.
