Modern relations between the two nations turned increasingly negative following the 14 July Revolution in Iraq in 1958, and subsequent overthrow of the Hashemite Monarchy which resulted in the country withdrawing from the Baghdad Pact. The Ba'ath Party gained power in Iraq in the 1960s, taking a more aggressive stance on border disputes. In the aftermath of the Islamic revolution in Iran in 1979, Saddam Hussein launched an invasion of Iran over border disputes and a desire to gain control of oil-rich areas in Iran's territory. The conflict lasted for eight years and ended in a stalemate. During the war, Iraq used chemical weapons and violence against Iraqi Kurds and Arabs, who were accused of colluding with Iran. While Iran did not support the multi-national coalition against Iraq's invasion of Kuwait in 1991, it housed many Shia political organizations opposing Saddam's rule.