The only area where Iran was not suffering major defeats was in Kurdistan. On 2 July, Iran belatedly set up a joint central command which unified the Revolutionary Guard, Army, and Kurdish rebels, and dispel the rivalry between the Army and the Revolutionary Guard. However this came too late, and Iran was believed to have fewer than 200 remaining tanks on the southern front, faced against thousands of Iraqi tanks. In addition, the US launched Operation Praying Mantis (which devastated Iran's navy on the same day as the 2nd Battle of Al Faw), and the US shooting down of Iran Air Flight 655 helped to convince Iran's leadership of their isolation and their inability to succeed in the war. The battles simultaneously highlighted the maturity of the Iraqi army, which had evolved throughout the war to the point where, during the Tawakal ala Allah Operations, it could carry out combined-arms operations utilising the different branches of the Iraqi Armed Forces as a single cohesive force. Iraqi chemical weapons contributed decisively to their victories, although it is hard to know how much of the damage inflicted upon the Iranians was caused by the gas. With the Iranian army in southern and central Iraq in retreat, various elements of the Iranian leadership, led by Ali Akbar Hashemi Rafsanjani (who had initially pushed for the extension of the war), persuaded Khomeini to sue for peace due to Iran's almost non-existent morale and impending bankruptcy. On 20 July 1988, Iran accepted Resolution 598, showing its willingness to accept a ceasefire, and on 20 August 1988, peace was officially restored. After a series of battles, in which Iraq had emerged as the victor, the leadership in Baghdad stated that they no longer desired to conquer Iranian territory. The success of the Iraqi armed forces had convinced the clerics of Iran that they could not attain their objectives on the field of battle and to accept the ceasefire.