- Square leg is also a fielding position in cricket; see Fielding (cricket).
Square Leg was a 1980 British government home defence Command Post and field exercise which tested the Transition to War and Home Defence roles of the MoD and Government. Part of the exercise involved a mock nuclear attack on the British Isles. It was assumed that 131 nuclear weapons would fall on Britain with a total yield of 205 megatons (69 ground burst; 62 air burst). This was felt to be a reasonably realistic scenario, although the report stated that a total strike in excess of 1,000 megatons would not be unexpected.
Mortality was estimated at 29 million (53% of the population); serious injuries at 7 million (12%); short-term survivors at 19 million (35%).
Square Leg was criticised for a number of reasons: the weapons used were exclusively in the high yield megaton range—with an average of 1.5 megatons per bomb—whereas a realistic attack based on known Soviet capabilities would have seen mixed weapons yields, including many missile-based warheads in the low hundred kiloton range; no targets in Inner London are attacked (for example Whitehall, the centre of British government); towns such as Eastbourne are hit for no obvious reason.
- Nuclear weapons and the United Kingdom
- World War III
- The Warsaw Pact operation Seven Days to the River Rhine
- RAF Greenham Common airfield
- Doomsday, Britain after Nuclear Attack, Stan Openshaw, Philip Steadman and Owen Greene, Basil Blackwell, 1983 ISBN 0-631-13394-1
- War Plan UK, Duncan Campbell, ISBN 0-09-150671-9
- The National Archives, FCO 46/2446, 2447, 2448
- Doomsday, Britain after Nuclear Attack, p. 102
- Doomsday, Britain after Nuclear Attack, p. 105