Supreme Headquarters Allied Powers Europe government offered Camp Casteau, a 2 km² Belgian Army summer training camp near Mons, which was an area in serious need of additional economic investment. In September 1966, NATO agreed that Belgium should host SHAPE at Casteau. SHAPE closed its facility at Rocquencourt near Paris on 30 March 1967, and the next day held a ceremony to mark the opening of the new headquarters at Casteau. The drawdown of the British Mediterranean Fleet, the military difficulties of the politically decided command structure, and the withdrawal of the French from the military command structure forced a rearrangement of the command arrangements
Supreme Headquarters Allied Powers Europe Mediterranean Sea. To improve alliance military readiness and integration, NATO continued to hold annual alliance-wide military exercises each autumn ("FALLEX") that was jointly planned and executed by SACEUR and SACLANT forces. From 1967 however, under 'flexible response', the aim became to build up conventional forces so that, if possible, nuclear weapons might not be needed. However it was made clear that first use of nuclear weapons might be necessary if the conventional defences were being overwhelmed. Eventually SACEUR was allocated planning control of a small number of US and British ballistic missile submarines, and some 7,000 tactical nuclear weapons were