Foreign forces were removed from French territory and French forces temporarily withdrawn from NATO commands.[12] 1st French Army, with its headquarters at Strasbourg, on the Franco-German border, was the main field headquarters controlling operations in support of NATO in West Germany, as well as defending France. Although France was not officially part of NATO's command structure, there was an understanding, formalised by regular joint exercises in West Germany, that France would go to the aid of NATO, should the Warsaw Pact attack. To that end, the Headquarters and two divisions of II (Fr) Corps were permanently stationed in West Germany, with the wartime mission of supporting NATO's US-led Central Army Group (CENTAG).[13]