Hard Rock (sometimes Operation Hard Rock or the Hard Rock exercise) was a British civil defence exercise planned by the Conservative government to take place in September-October 1982. One of a series of regular national civil defence exercises, it followed Square Leg in 1980. As the public reaction to the scale of devastation forecast in Square Leg was poor the planner deliberately scaled down the number of warheads supposed for Hard Rock. Despite this the Campaign for Nuclear Disarmament (CND), who opposed nuclear warfare and were against civil defence exercises, suggested that such as attack as Hard Rock anticipated would have led to the deaths of 12.5 million people. Since 1980 many British local authorities, who played key roles in civil defence planning, had become nuclear-free zones, opposed to nuclear weapons and nuclear power. Many of these authorities refused to take part in Hard Rock, though finance and the unofficial policy of the Labour Party also played a part. By July 20 local authorities, all Labour-run, had indicated their refusal to take part and 7 more would only take part in a limited manner. Hard Rock was postponed indefinitely, effectively cancelled. In response the government passed the Civil Defence (General Local Authority Functions) Regulations 1983, compelling local authorities to take part in civil defence exercises. Planning During this period the British government carried out national civil defence exercises every 2-3 years to test the country's preparedness for nuclear war. Hard Rock was scheduled to be run in September-October 1982 and would have been the largest civil defence exercise for 15 years. Planning for Hard Rock was started by the National Council for Civil Defence in 1980. The attack scenario for the previous simulation, the 1980 Square Leg exercise, had been leaked to the press and the Campaign for Nuclear Disarmament (CND). This scenario envisaged more than 200 megatons of nuclear weapons being detonated on the country, a quantity in line with all other British civil defence exercises since the 1970s. The public response to the projected high casualty rates and widespread destruction had been poor so the Hard Rock planner deliberately assumed an attack scenario with fewer weapons, totalling less than 50 megatons, and avoiding strikes on some obvious targets such as American air bases. Journalist and writer on Cold War military secrets Duncan Campbell noted that no missiles were assumed to be targeted at London, Manchester, Edinburgh, Liverpool, Bristol