Peacekeeping in Bosnia: MOSTAR, Bosnia -- The team of American auditors had just begun studying the records inside a Bosnian bank suspected of criminal connections when an angry, shouting mob of ethnic Croats appeared on the street outside. Within minutes, the protesters, some of them waving guns, had pressed against the doors and closed off escape. "Green Box! Green Box!" screamed an Italian police captain accompanying the auditors, over and over into his military radio. But Green Box -- a code word for NATO troops deployed outside the town of Grude to protect the Western officials inside the bank -- never showed up.