US troop levels will be increased by 12,000 in the run up to the election, from 138,000 to 150,000. There were 148,000 in country on May 1, 2003 when George W. Bush declared "Mission Accomplished."
According to Army Brig Gen David Rodriguez, "the purpose [of the troop increase] is mainly to provide security for the elections. But it's also to keep up the pressure on the insurgency after the Falluja operation."
Robert Burns of the AP notes that the need for more American troops "underscores the fact that, despite enormous effort and cost, American commanders have yet to train and equip enough Iraqis for security duty." "Insurgents have managed to intimidate many Iraqis into not cooperating with the Americans,"according Lt. Gen. Lance Smith, deputy commander of Central Command.
The increased troop levels will persist until mid-March 2005. The increase is achieved by extending tours, including a second extension for the First Cavalry Division's Second Brigade. The normal 7 and 12 month deployments have been turned into 9 and 14 month terms. The NYT has details on the extensions.