UK Trident renewal: antecedents and decision-making

In March 2007 the British government of Tony Blair officially decided to extend the life of the Trident submarine deterrent. This was painted by the Labour government as a continuation of the original Trident agreements made by the Conservative administration of Margaret Thatcher in 1980 and 1982. The Blair government stated at the time that the Ministry of Defence was advocating an immediate decision due to the age of the four Vanguard-class submarines and the timescale needed for designing and building the submarines and warheads. Subsequent government’s, including the present Conservative government led by David Cameron, have stuck to this decision and this rationale with the ‘Main Gate’ decision now due in 2016. In pitching a case for Trident replacement there has been a clear recognition that although the strategic environment has changed substantially in the twenty first century there remains a remarkable continuity between the first Trident decision in 1980 as well as the original Polaris Sales Agreement (PSA) of 1963. The 2015 Strategic Defence and Security review maintained the renewal decision. This chapter will examine the continuities between governments on the replacement question.