The European Union accused Iran yesterday of having documents that show how to make nuclear warheads and joined the United States in warning Tehran it faced referral to the UN Security Council for possible sanctions. Iran, meanwhile, suggested that it was considering a compromise to reduce tensions. Britain, in a statement on behalf of the 25-nation bloc, offered new negotiations meant to lessen concerns over Iran’s insistence that it be in full control of uranium enrichment — a possible pathway to nuclear arms.Full Story