UNITED NATIONS (AP) - The U.N. Security Council approved a brief extension of U.N. peacekeeping operations in Bosnia on Friday, giving diplomats time to tackle a demand to exempt Americans from prosecution by the world's first permanent war crimes tribunal. The United States has threatened to end its participation in U.N. peacekeeping operations if the council does not grant Americans who take part immunity from arrest and prosecution by the International Criminal Court, which becomes a reality July 1. The council had been expected to extend the U.N. civilian police mission in Bosnia and the authorization for the NATO-led peacekeeping...