An Israeli missile attack that killed 10 civilians sheltering in a U.N. school here early this month prompted a call for restraint from the U.S. government over what the State Department described as a disgraceful act. Yet what Israel used in that Aug. 3 strike, according to the United Nations, was a Hellfire missile a U.S.-made weapon. The incident was one of many in the ongoing six-week-old war in the Gaza Strip in which weapons sold to Israel by the United States and some European nations have played a prominent role.