dec 30, 1972 - US B-52 bombardment of Cambodian countryside in support of Lon Nol forces reaches its peak. 250,000 tonnes of bombs are dropped in seven months, before US Congress calls a halt to the bombing on 15 August. Toll from 1969 to 1973: 50,000 to 150,000 civilian deaths from the bombing. Pol Pot forces use the bombing's killing and destruction as recruitment propaganda and as an excuse for the abandonment of moderate socialist policies in the insurgent zones. Purges of moderate communists suspected of disloyalty t (Timeline)