The governor, with consent of congress, is authorized to enter into compacts and agreements with governors of bordering states concerning guarding and patrol of bridges crossing the common boundaries of said states, and for the patrol of said common boundaries. In any such compact or agreement the governor is authorized to permit militia of any bordering state to enter into areas of this state adjacent to said border, or to send militia of this state into areas of any bordering state adjacent to the common boundary as may be necessary to provide effective protection.
RCW 38.08.100