The Iraqi government and Arab countries have broken into bitter squabbling ahead of a Baghdad conference on Saturday that the United States had hoped would finally unite them in efforts to stabilize the war-torn nation. Sunni-led Arab governments plan to use the conference to press for a greater Sunni role in Iraq. That has rankled Iraq's Shi'ite leaders, who believe the Arabs are trying to reverse their new-found power after decades of being marginalized under Sunni minority rule. The dispute reflects the complicated tensions that are likely to surface at the Baghdad meeting, which gathers diplomats from Iraq's Arab neighbors, Iran, the United States, Turkey and the permanent members of the UN Security Council. Arab states are likely to try to rally the United States behind their demands, increasing the pressure on Baghdad. Iran has vowed to support its Shi'ite allies in the Iraqi government - but is also concerned the US will press it on accusations that Teheran is supporting Shi'ite militants fueling Iraq's bloodshed.