The United Kingdom had the experience of at least five different kinds of emergency throughout the twentieth century. The first and most serious is war, though not all wars (including the wars in Iraq and Afghanistan) create or created national emergencies. Nevertheless, the world wars of 1914–1918 and 1939–1945 almost certainly did, especially in the latter case with its risk – albeit short-lived – of invasion by a foreign power. The other causes of emergency were: second, the long-term internal conflict in Northern Ireland in what seemed like a separatist armed struggle, with one community pitted against another, and against the State (1969–2007); third, short-term but large-scale industrial action, which in at least one case (1926) was thought to border on the subversive; while the fourth has been an array of natural disasters, sometimes caused by adverse weather conditions, and sometimes caused by disease; finally, and most recently, there is the threat posed by international terrorism in the wake of 9/11 and our experiences in London in July 2005. Although emergency situations can thus arise for a host of reasons, it might be argued that the foregoing list is far from complete, with a sixth category of emergency being the various economic and fiscal crises that have engulfed the country from time to time, notably in 1931, when emergency powers were taken, and again after the end of World War II, when the country was financially exhausted by the demands of conflict.