U.N. Secretary-General Boutros Boutros-Ghali cleared the way for promptNATO airstrikesifSerbs, as expected, attack the "safe area" of Gorazde. Trying to shore up fast-eroding domestic support for the Bosnian arms embargo, President Clinton declared the U.N. move "the last chance" for the international peacekeeping mission in Bosnia: "You can't go about the world saying you're going to do something and then not do it." If the House follows the Senate with a veto-proof lifting of the ban, Clinton fears the ensuing warfare will trigger a massive U.N. withdrawal requiring escort by 25,000 U.S. troops. TIME's Dean Fischer reports that NATO officials are moving to expand their mandate to attack Serbs if they threaten any remaining safe haven. Clinton, asked today why the Serbs should take the new threat seriously, said: "If the U.N. fails the next time, there will be a different course." But Serb Gen. Ratko Mladic, indicted as a war criminal Wednesday, thumbed his nose at the American lawmakers who would arm the Bosnian Muslims. "If they lift the embargo," he said, "I'll just eventually end up capturing all of them."