Formed initially as an air group in 1919 during the Latvian War of Independence, service was halted in 1940 following the Soviet occupation. Re-established in 1992, the Latvian Air Force is the aeriel branch of the National Armed Forces of Latvia but has no air combat capability. The defence of Latvian air space is maintained by NATO, with an arrangement known as the Baltic Air Policing whereby international detachments of 4 aircraft are based in Lithuania and rotated in 4 monthly intervals.