In 1949, the North Atlantic Treaty Organization (NATO) military alliance was established. Portugal, the United States, the United Kingdom, Canada, and various (other) western European countries were charter members of NATO. By reason of the NATO alliance, Lajes was available for use by those countries, and the use of Lajes was one of Portugal's primary contributions to the alliance. However, use of Lajes Field by the United States military is secured by a Status of Forces Agreement (SOFA) outside the NATO SOFA.
