Troop Drawdown as Early as December?

A top adviser to Gen. David Petraeus, the chief U.S. commander in Iraq, says the general's assessment of the current situation on the ground would allow a drawdown of the surge to begin early next year or possibly in December.

The aide, who is directly involved in operational and strategic planning, says the timeline would not be firm, but would be based on the security situation. Petraeus would then make another assessment in six months about whether to continue that drawdown.

There is consensus among the military leadership about beginning the drawdown of the surge early, but beyond that there is some real tension about the way forward. If the surge were to continue on its current course, forces involved wouldn't start coming home until April.

The Joint Chiefs, particularly Army Chief of Staff George Casey, and CENTCOM have argued for a quicker reduction in U.S. force levels and to change the central mission. The current counterinsurgency mission is for U.S. troops to protect the population through means such as patrolling the streets and having a visible presence in the neighborhoods.

Casey and CENTCOM commander Adm. William "Fox" Fallon have argued that the central mission should be training and supporting the Iraqi troops. Petraeus' staff dismisses this as the "been-there-done-that" strategy.

"It's been painful" to deal with Fallon, the source says. "He's been for mission change and a rapid drawdown."

When the drawdown begins, Petraeus would first reduce force levels in Anbar province and northern Iraq. He believes it would be a mistake to do so now.

"We have our foot on al Qaeda's throat and we are still going after them," said the source, "but they are not defeated yet."