London police will be especially over-stretched next week when up to 4,000 officers are expected to be deployed at an arms fair in east London. The biennial fair, Defence Systems and Equipment International (DSEi), has cost the Metropolitan Police over £4 million on each of the last two occasions it has been held. Assistant Commissioner Steve House said in 2005 that DSEi was "denuding London of policing at a time of unprecedented demand". DSEi will take place at the Excel Centre from Tuesday 11th - Friday 14th September, with over 1,200 companies expected to promote weaponry from handguns to fighter...