Israel Tells the U.S. It Will Retaliate if Attacked by IraqBy MICHAEL R. GORDON JERUSALEM, Sept. 21 — Prime Minister Ariel Sharon has informed the Bush administration that he plans to strike back if Iraq attacks Israel, according to Israeli and Western officials. Mr. Sharon's statements, made privately to senior American officials in recent weeks, represent a major shift in Israeli thinking since the 1991 Persian Gulf war, when 39 Iraqi Scud missiles struck without any Israeli response. Advertisement The prime minister's position reflects a widespread belief among Israeli politicians and generals that Arab leaders perceived Israel's restraint in 1991...