Vast stretches of ocean separate nations and military installations across a region defined by dispersed islands, long supply lines and limited infrastructure.
They may consist of one or more military branches such as an army, navy, air force, space force, marines, or coast guard. The main task of a military is usually defined as defence
Within the Department of Defense, the military departments (Department of the Army, Department of the Navy, and Department of the Air Force) are civilian led entities that oversee
Apr 30, 2026 · The Department of War is America's largest government agency. Our mission is to provide the military forces needed to deter war and ensure our nation's security.
Learn how to join the military. Find benefits and services as a member or veteran, including how to apply for housing, financial, health, and other support.