Troops cannot be withdrawn fast due to their large number and the colossal amount of military hardware that must be removed safely.
- Option 1 would remove U.S. forces beginning in October 2009 at a rate of 14,400 troops per month to complete the withdrawal by the end of June 2010.
- Option 2 would draw forces down more rapidly—at a rate of 17,500 service members per month—starting in October 2009 and removing all troops by May 2010.
- Option 3 would conduct the withdrawal at the same rate as Option 2—17,500 troops per month—but begin after Iraq’s elections, scheduled for January 2010. Under this option, withdrawal would be complete by September 2010.
As a candidate for President, I made clear my support for a timeline of 16 months to carry out this drawdown, while pledging to consult closely with our military commanders upon taking office to ensure that we preserve the gains we’ve made and protect our troops. Those consultations are now complete, and I have chosen a timeline that will remove our combat brigades over the next 18 months. Let me say this as plainly as I can: by August 31, 2010, our combat mission in Iraq will end.Obama's pledge indicates he was going with Option 3, which means the draw-down would not begin until January 2010.
The withdrawal would take 16 months mostly for logistical reasons. "The withdrawal of significant numbers of U.S. military personnel before the Iraqi elections could increase security risks during a time of high tensions in Iraq," the Congressional Budget Office wrote. "And removing U.S. forces and their associated equipment faster than the Administration has planned could place U.S. forces that remain in Iraq at greater risk of attack and result in the buildup of equipment at Kuwaiti ports awaiting shipment to the United States or at U.S. ports awaiting transportation to bases in the United States."
The United States had roughly 37 brigade equivalents in Iraq as of September 2009. Removing the equipment will require moving roughly 37,000 military vehicles, including trucks, armored vehicles, almost 400 helicopters, large quantities of communications gear, small arms, and medical equipment.
Materiel could weigh 750,000 tons and could fill between 37 and 74 large sealift ships. Transporting roughly 13,500 tons of usable ammunition could require three additional ships in the strategic sealift fleet that are configured to carry ammunition.
All told, up to 80 shiploads of material weighing more than 750,000 tons could need to be moved from Iraq to the United States, Europe, or South Korea.

