Was the Marshall Plan simply intended to guarantee the sale of U.S. exports and prevent Western European and Japanese independence? Why is U.S. support for Israel crucial to national security policy? Is China a threat? How should the United States combat terrorism?

U.S. national security is no longer based on a natural defense involving traditional isolationism and friendly neighbors. With international trade an increasing goal of the United States, and the transportation of cheap products an ever-growing trend, U.S. interests outside national boundaries will continue to develop as will the need to provide security for those interests. This primer covers the Cold War and post-Cold War decades, identifies changing threats to national security, and introduces the agencies and individuals that shape national security policy.