Reserve and National Guard units perform as active-duty service members on a part-time basis. These troops train close to home and deploy as needed to aid in international conflict or domestic disaster relief.
The United States Army is the largest and oldest branch of the United States armed forces and is responsible for land-based military operations.
The smallest branch of the U.S. Military, the Marine Corps is often first on the ground in combat, utilizing the mobility of the Navy from the sea.
The Navy defends the right to travel and trade freely on the world's oceans while protecting national interests overseas.
The mission of the U. S. Air Force is to fly, fight and win…in air, space, and cyberspace.