Mr Hammond said ministers intended a greater integration of regular and reserve components and an increased use of contractors, and that the "reserve will be a vital, integrated component of the army".

BBC: Hammond promises 'forward-looking, modern' Army

While some of the security cooperation efforts undertaken with allies and potential partners are carried out directly by active duty U.S. armed forces personnel, reserve and National Guard components also play an important role.

CENTERFORSECURITYPOLICY: A stimulus for African security

As essential components of our military, the National Guard and Reserve have helped carry that legacy forward.

WHITEHOUSE: The White House