On Eve of Election in Bosnia, Peace Is a Last Resort
Much of Bosnia has been devastated by war; main hope of an exhausted people is that fighting never resume; most Bosnians seem beyond caring about abstract goal, championed by United States, of creating common institutions that will unify Croats, Serbs and Muslims; to many, current de facto partition is an end to conflicts that have caused so much misery and grief; in addition to deep antipathy to war, there is also finger-pointing: Muslims, Croats and Serbs blame their opponents for the carnage; in this atmosphere, first elections in six years will be held on Sept 14; photos; map (M)