hostile neighbor." Their competition was especially fierce after the 1968 Baathist coup and the concurrent withdrawal of British forces from the Persian Gulf region. Also in 1921, the British played a role in the 1921 Persian coup d'etat, which led to the rise of the Pahlavi dynasty as rulers of Iran in 1925. Reza Shah's Iran was in economic trouble, and he sought good ties with his neighbors in the 1920s—including Iraq. Iran and Iraq were staunchly anticommunist and pursued pro-West policies. They also cooperated in preventing the emergence of a Kurdish state. Iraq, supported by other Arab states, resisted Iranian influence under the Shah in the 1970s (which was backed by the United States as part of the Twin Pillars policy). This took the form of supporting insurgencies against the Shah in Khuzestan Province and Iranian Balochistan. The Shah, in turn, attempted to organize a coup against Saddam Hussein in 1971 and helped Sultan Qaboos of Oman quell an Iraqi-backed rebellion. He also backed a Kurdish rebellion led by Mustafa Barzani. In 1975, Iran and Iraq signed a demarcation agreement stemming from the Kurdish rebellion, which remained in stalemate. Iran–Iraq War The Iranian Revolution in 1979 drastically changed Iran–Iraq relations for 24 years. War broke out between Iraq and Iran in September 1980. Eight years of fighting left around 600,000 dead and caused huge disasters for both sides, thereby grimly blistering ties between Tehran and Baghdad. The United Nations (UN) issued Resolution 598 in July 1987, demanding an unconditional ceasefire between the two nations. Both nations adopted the resolution ending the war in August 1988. Post-war reconciliation Although Iran condemned the Iraqi invasion of Kuwait, the former enemies reestablished diplomatic relations in October 1990; one month later, Iranian Foreign Minister Ali Akbar Velayati visited Baghdad. In January 2002, one year before the U.S.-led Iraq War, the bilateral relations improved significantly when an Iranian delegation led by Amir Hussein Zamani visited Iraq for final negotiations to resolve the conflict through talks on issues of prisoners of war and the missing in action. Post-Saddam After the US-led war on Iraq started in 2003, Tehran strongly opposed the invasion, calling for a key role of the UN in Iraq's reconstruction. Iran then offered assistance to Iraq's post-war reconstruction and bilateral relations began to improve. In May 2005, a transitional government led by Ibrahim al-Jaafari of the pro-Iran Islamist Dawa party was established