Throughout its history the United States has acted to protect its territories, citizenry, and interests at home and abroad. The terrorist events of September 11, 2001, heightened public interest in national security matters, and the U.S. government has asked all Americans to be watchful, suspicious, and alert to signs of danger or potential security threats. Since September 11, 2001, rarely does a day pass without media attention focused on national security issues.
As new conflicts emerge and power shifts occur worldwide, America's role and responsibilities in terms of ensuring its own and other nations' security is evolving. As a global leader, the United States is challenged to continually revisit its fundamental values and to reset its national security agenda accordingly.