This front was barely won by Iran. First, there were commonwealth troops heading from India and Iraq (and reinforced by 5 SS battalions on loan from the Greater German Reich (Hitler is an American---Version 1)). But, the Axis forces had little, if any, experience of desert warfare, and US fighters given to Iran were a thorn in the Luftwaffe's side. After Tehran, the Iranians began a march to delhi, where the Pakistani insurgents sided with them and captured Delhi by late 1942. the British responded to the attacks on their Indian empire by deploying Mustard Gas on the Iranian troops, which significantly slowed the advance.