Comrades: Communism, a World History by Robert Service Macmillan £25, pp624 Most chilling is Service's account of how the clinical targets of state industrial planning during Stalin's five-year plans were replicated in the extermination of political opponents. Decree 00447 in 1937 stipulated that 259,450 'anti-Soviet elements' should be taken into custody; a precise 28 per cent of them were to be executed. Stalin's famine in Ukraine in the Thirties is eclipsed by the 30 million estimated killed in Mao's Great Leap Forward. The most horrible quotation in the book is Mao's: 'How many people would die if [nuclear] war breaks...