طنب الكبرى
In 1971, Iraq (now under Saddam's effective rule) broke diplomatic relations with Iran after claiming sovereignty rights over the islands of Abu Musa, Greater and Lesser Tunbs in the Persian Gulf following the withdrawal of the British. As retaliation for Iraq's claims to Khuzestan, Iran became the main patron of Iraq's Kurdish rebels in the early 1970s, giving the Iraqi Kurds bases in Iran and arming the Kurdish groups. In addition to Iraq fomenting separatism in Iran's Khuzestan and Balochistan, both states encouraged separatist activities by Kurdish nationalists in the other state. From March 1974 to March 1975, Iran and Iraq fought border wars over Iran's support of Iraqi Kurds. In 1975, the Iraqis launched an offensive into Iran using tanks, though the Iranians defeated them. Several other attacks took place; however, Iran had the world's fifth most powerful military at the time and easily defeated the Iraqis with its air force. As a result, Iraq decided against continuing the war, choosing instead to make concessions to Tehran to end the Kurdish rebellion.