Iraq question: How many troops to cut?

? New calls from lawmakers to begin withdrawing U.S. forces from Iraq may trouble the White House but are not too out of step with scenarios envisioned by war commanders.

The disagreement mainly is about how deeply to cut, not when to begin.

Anti-war Democrats and some Republicans want to bring all combat troops home in a matter of months. Generals in Iraq favor starting the transition next year from a predominantly combat role, but only gradually; this approach would leave a six-figure force in Iraq for the next president to command.

About 162,000 U.S. troops are in Iraq now. Some 30,000 were added between January and June as the main element of President Bush’s revised strategy to stabilize Baghdad. The first of five Army brigades in that buildup is expected to go home by April, if not a few months earlier.

Lt. Gen. Ray Odierno, the top day-to-day commander of U.S. forces in Iraq, said this month that all five brigades probably would be out of Iraq – and not replaced – by August 2008. That would take the troop total back down to roughly 132,000.

It is not clear how much lower the total might go by the time Bush leaves office in January 2009. For some military officials, the hope is below 100,000 by then.

A war-fighting plan by Gen. David Petraeus, the top U.S. commander in Iraq, and Ambassador Ryan Crocker that went into effect July 26 foresees a significant U.S. role at least until 2009.

The plan does not contain troop numbers or withdrawal schedules. Rather, it sets a goal of achieving “sustainable security” by the summer of 2009.