Amid a world of pitiless competition, David Cameron is serving the national interest by leading the drive to sell British-made weaponry to our allies in the Gulf. No less than 300,000 jobs depend on Britain’s defence industry, which serves as our biggest exporter of manufactured goods and keeps this country at the forefront of technological advance. So there should be no hand-wringing: the Prime Minister was entirely right to promote the possible sale of 60 Typhoon fighters in the United Arab Emirates.