Tensions between Iraq and Iran were fuelled by Iran's Islamic revolution and its appearance of being a Pan-Islamic force, in contrast to Iraq's Arab nationalism. Despite Iraq's goal of regaining the Shatt al-Arab, the Iraqi government initially seemed to welcome the Iranian Revolution, which overthrew Shah Mohammad Reza Pahlavi, who was seen as a common enemy. There were frequent clashes along the Iran–Iraq border throughout 1980, with Iraq publicly complaining of at least 544 incidents and Iran citing at least 797 violations of its border and airspace.