President Clinton indicated he would back off an October 15 deadline for Serbs to accept a peace plan. Clinton had so far used the stick of arming the Muslims to convince the Serbs to reverse their rejection of the internationally backed proposal. But the Bosnian Muslims, afraid the Serbs would launch a deadly offensive in anticipation of the lifting of the arms embargo, told Clinton "they may be interested in deferring any action on that for four to six months," the President said today. Russian President Boris Yeltsin, a Serb ally, added his two cents during his current visit to Washington, saying he would oppose Clinton's threatened action. All this pressure was probably the best thing for the Prez's beleaguered Bosnia plan: "It gave Clinton an opportunity to back out of something that was ill-advised in the first place," says TIME Central Europe bureau chief James L. Graff.