The Utility of Force - The Art of War in the Modern World by Rupert Smith Penguin, HK$160 At the end of the cold war in 1991, there were 75,000 tanks on either side of the iron curtain. Tactics and strategy were based on armour and a belief in 'industrial war'. Rupert Smith, a former British general who retired in 2002, was commander of the UK Armoured Division in the first Gulf war and, most recently, deputy supreme commander of Nato forces. He says in The Utility of Force that 'industrial war', fought since the days of Napoleon involving huge armies, ended when the atomic bomb was dropped on Hiroshima. Despite enormous resources spent on better ways to kill people, the most effective weapon is the machete, as wielded in Rwanda - one million people killed in 100 days. Wars are now too expensive, in both casualties and equipment. Smith says soldiers, and the politicians who direct them, need to understand war has become very local, people versus people. Modern war, he says, requires clear political objectives based on informed foreign policy, not a reliance on military might.