The USSR's invasion of Afghanistan was only one sign of insecurity in the region, also marked by increased American weapons sales, technology, and outright military presence. Saudi Arabia and Iran became increasingly dependent on American security assurances to manage both external and internal threats, including increased military competition between them over increased oil revenues. Both states were competing for preeminence in the Persian Gulf and using increased revenues to fund expanded militaries. By 1979, Saudi arms purchases from the US exceeded five times Israel's. Another motive for the large scale purchase of arms from the US by Saudi Arabia was the failure of the Shah during January 1979 to maintain control of Iran, a non-Arabic but largely Shiite Muslim nation, which fell to a theocratic Islamist government under the Ayatollah Ruhollah Khomeini in the wake of the 1979 Iranian Revolution. Saudi Arabia, on the other hand, is an Arab, largely Sunni Muslim nation headed by a near absolutist monarchy. In the wake of the Iranian revolution the Saudis were forced to deal with the prospect of internal destabilization via the radicalism of Islamism, a reality which would quickly be revealed in the seizure of the Grand Mosque in Mecca by Wahhabi extremists during November 1979 and a Shiite revolt in the oil rich Al-Hasa region of Saudi Arabia in December of the same year. In November 2010, Wikileaks leaked confidential diplomatic cables pertaining to the United States and its allies which revealed that the late Saudi King Abdullah urged the United States to attack Iran in order to destroy its potential nuclear weapons program, describing Iran as "a snake whose head should be cut off without any procrastination."