While the majority of Muslims in Iraq are Shia, the country has been ruled for decades by Sunni-dominated governments under the Ottoman Empire, the British-installed Hashemites, and the Ba'athists. Under the rule of Saddam Hussein, Iraq was hostile to both Iran and Saudi Arabia and acted as a counterbalancing regional power. The American-led invasion in 2003 caused a power vacuum in the region. With the antagonistic Ba'athist regime removed, Iran sought a more friendly Shia-dominated government and supported sympathetic rebel factions as part of an effort to undermine the coalition, which Iran feared would install a government hostile to its interests.