A worldwide sell-off for stocks is slamming onto Wall Street on Tuesday, and oil prices are leaping even higher as worries rise that the war with Iran is widening and may do more sustained damage to the global economy than feared. The S&P 500 dropped by 1.8 per cent in early trading. The Dow Jones Industrial Average was down 907 points, or 1.9 per cent, as of 9.35am Eastern time, and the Nasdaq composite was 2.1 per cent lower. It was just a day ago that US stocks opened with sharp losses, only...