the smaller, lighter Red Beard bomb, which entered service in 1960, by the mid-1960s Canberras and the Royal Navy's Fleet Air Arm were able to deliver nuclear weapons, but their power was insignificant compared with that of the 109 Victor and Vulcan bombers. The V bombers were formally relieved of their role as the deliverer of the UK strategic nuclear deterrent, which officially passed to the Polaris ballistic missile submarines of the Royal Navy on 1 July 1969. The last Blue Steel mission was flown on 21 December 1970. Five Vulcan squadrons continued to serve with the WE.177B weapon in a tactical role in Europe with SACEUR. Nos 9 and 35 Squadrons moved to RAF Akrotiri in Cyprus, where they replaced Canberra bombers in support of CENTO and operations on NATO's southern flank. They were withdrawn in 1975 in the wake of the Turkish invasion of Cyprus. Six squadrons of Vulcans were still assigned this role with the WE.177 weapon in 1981. The last four remaining squadrons were about to disband in 1982 when called upon to assist in the Falklands War. Conventional mission Suez crisis The first V bomber to see combat use with conventional bombs was the Valiant in Operation Musketeer, the Anglo-French military response in the Suez Crisis in 1956. It was the first and only time the Valiants dropped bombs in combat operations. RAF units began deploying to Malta in September 1956, and when Israel attacked Egypt on 29 October 1956, four Valiant squadrons—Nos 138, 148, 207 and 214 Squadrons—were based at RAF Luqa. No. 138 Squadron was the only one with a full complement of eight Valiants; Nos 148 and 207 each had six, and No. 214 had only four. The initial objective was to neutralise the Egyptian Air Force, which was believed to have about 100 Mikoyan-Gurevich MiG-15 jet fighters and 30 Ilyushin Il-28 twin-engine jet bombers. The Egyptian early-warning radar system was known to be non-operational due to lack of maintenance and spare parts, so the bombers were ordered to operate at night when the visually-controlled defences would be least effective. This meant a reversion to the tactics used by Bomber Command in the Second World War. The Valiants were neither trained nor equipped for such a mission. Not all of the Valiants were equipped with the Navigation and Bombing System (NBS) and it was not serviceable in all of those that were.