The Military Reserves

Each armed service has a reserve component of part-time members who hold civilian jobs, train about one weekend a month and two weeks a year, and can be ordered to active duty. There are seven: the Army Reserve, the Navy Reserve, the Marine Corps Reserve, the Air Force Reserve, and the Coast Guard Reserve, which are federal forces, and the Army National Guard and the Air National Guard, which also serve their states under governors. The Space Force is folding part-time members into a single component under a 2023 law. The Selected Reserve, members in units who train regularly, numbers roughly three quarters of a million, and more than 200,000 former service members in the Individual Ready Reserve can be recalled.

The reserves were long a strategic backup for a major war, but since the 1991 Gulf War and especially after September 11, 2001, they have become an operational force, with hundreds of thousands of reservists and Guard members mobilized for Iraq and Afghanistan. The President can order up to 200,000 selected reservists to active duty for up to 365 days without declaring an emergency, and many more after declaring a national emergency or when Congress declares war. The Uniformed Services Employment and Reemployment Rights Act of 1994 requires employers to rehire reservists after service and bars discrimination against them.

Repeated deployments strained families and employers and made recruiting harder, and the services have debated how much to rely on part-time forces, which cost less in peacetime but take time to mobilize. Reserve leaders seek more equipment and training money, some budget analysts propose shifting more missions to the reserves to save money, and others warn that frequent deployments wear part-time forces out. The National Guard's dual role under governors and the President became a flashpoint in 2025, when Guard troops were federalized and sent to several cities over the objections of some governors.