In a special edition of HARDtalk from the shores of Lake Como in Italy, the venue for the annual Ambrosetti Forum on international affairs, Stephen Sackur talks to John Bolton, one of America's most vociferous neoconservatives and a former US ambassador to the United Nations under George W Bush. America's economy is misfiring, her military is stretched and the number of global challenges is multiplying - is it time to acknowledge the era of American supremacy is over?
