The United States Strategic Command is one of the eleven unified combatant commands in the United States Department of Defense. Headquartered at Offutt Air Force Base, Nebraska, USSTRATCOM is responsible for strategic nuclear deterrence, global strike, and operating the Defense Department's Global Information Grid. It also provides a host of capabilities to support the other combatant commands, including integrated missile defense; and global command, control, communications, computers, intelligence, surveillance, and reconnaissance (C4ISR). This command exists to give "national leadership a unified resource for greater understanding of specific threats around the world and the means to respond to those threats rapidly".