Iran Defies Demand of Nuke Watchdog Agency VIENNA, Austria - Defying a key demand set by 35 nations, Iran announced Tuesday it has started converting raw uranium into the gas needed for enrichment, a process that can be used to make nuclear weapons.    Iran's president, Mohammad Khatami, vowed his country will press ahead with its nuclear program - which he insisted is peaceful - even if it means a rupture with the U.N...