The end of the Cold War has wrought great changes in the global security environment and reopened the policy-making debate concerned with the most effective means of ensuring the security of the international system, states, and their individual citizens. The initial reaction in some quarters following the end of the Cold War was that the collapse of the USSR and global communism represented a decisive victory for the superior military power of the US and its alliance partners. The decision of President Ronald Reagan's administration in the early 1980s to seek strategic parity (or even superiority) over the USSR by embarking on a quantitative and qualitative build-up of US military forces through such programmes as SDI (Strategic Defence Initiative) appeared to be vindicated. The Reagan administration's defence policy was thought to have convinced Soviet leaders of the futility of expansionism and forced them to try to match increased levels of US defence expenditure, which in turn crippled the USSR's economy and forced it out of Cold War competition.1 Following on from the assumption that the outcome of the Cold War had been decided by the crushing weight of US military power, the expectation was that the post-Cold War peace and security environment would also be determined to a large extent by this factor. Although President George Bush's administration, which oversaw the end of the Cold War, was certainly conscious of the need for retrenchment in defence spending and overseas military commitments in order to reap the benefits of the ‘peace dividend’, the events of the Gulf War of 1990–91 confirmed for the Bush administration the central role of military power in post-Cold War security, and encouraged the President to lay out in his 1991 State of the Union address a vision of a ‘New World Order’ in which national and global security would be guaranteed by collective military intervention under US leadership.2