32 USC 703 - Purchases of supplies by States from Army or Air Force
(a) Subject to the approval of the Secretary of the Army, any State, the Commonwealth of Puerto Rico, the District of Columbia, Guam, or the Virgin Islands may buy from the Department of the Army, for its National Guard or the officers thereof, supplies and military publications furnished to the Army, in addition to other supplies issued to its Army National Guard. On the same basis, it may buy similar property from the Department of the Air Force. A purchase under this subsection shall be for cash, at cost plus transportation.
(b) In time of actual or threatened war, the United States may requisition for military use any property bought under subsection (a). Credit for the return in kind of property so requisitioned shall be given to the State, the Commonwealth of Puerto Rico, the District of Columbia, Guam, or the Virgin Islands from which it is received.
(c) Proceeds of sales by the Department of the Army and the Department of the Air Force under this section shall be credited to the appropriations from which the property was purchased, shall not be covered into the Treasury, and may be used to replace property sold under this section.