The troop level for the initial invasion of Iraq was controversial throughout the run-up to the war, particularly among U.S. military personnel. In 1999, then head of United States Central Command Marine General Anthony Zinni (ret.) organised a series of war games known as Desert Crossing to assess an invasion aimed at unseating Saddam Hussein. His plan, which predicted much of the violence and instability that followed the actual invasion, called for a force of 400,000 troops.[12] Consistent with the Desert Crossing scenarios, the original U.S. army plan for the invasion of Iraq contemplated troop levels of up to 500,000, but Secretary of Defense Donald Rumsfeld declared this plan "the product of old thinking and the embodiment of everything that was wrong with the military", and decided on an invasion force of approximately 130,000, bolstered by some 45,000 British troops and a handful from other nations.[13] The plan to invade with a smaller force was publicly questioned by then Army Chief of Staff General Eric Shinseki, who, during a February 25, 2003 Senate Armed Services Committee hearing, suggested that an invasion force would be "on the order of several hundred thousand soldiers."[14] In a November 15, 2006, hearing of the same committee, General John Abizaid, then head of U.S. Central Command, confirmed that "General Shinseki was right that a greater international force contribution, U.S. force contribution and Iraqi force contribution should have been available immediately after major combat operations."[15]