DEFENCE group Chemring has had a good war. Demand is booming for its decoy systems, used to shield aircraft against missiles. It sold £15m worth to the US Army to protect helicopters in Iraq, helping lift first-half profits 19% to £5.1m pretax, dividends 10% to 2.8p. It is also chasing major contracts to supply civilian aircraft. At 436 1/2p, down 1/2p, the shares are 13 times likely earnings.