WASHINGTON—U.S. military officers in Afghanistan have drawn up preliminary proposals to withdraw as many as 5,000 troops from the country in July and as many as 5,000 more by the year’s end, the first phase of a U.S. pullout promised by President Barack Obama, officials say.

The proposals, prepared by staff officers in Kabul, are likely to be the subject of fierce internal debate in the White House, State Department and Pentagon—a discussion influenced by calculations about how Osama bin Laden’s death will affect the Afghan battlefield. The plans were drafted before the U.S. killed the al Qaeda leader, and could be revised. They have yet to be formally presented to Gen. David Petraeus, the commander of U.S. forces in Afghanistan, who must then seek White House approval for a withdrawal.

If approved by top military officers and the president, an initial withdrawal of 5,000 would represent a modest reduction from the current 100,000 U.S. troops in Afghanistan, allowing the military to preserve combat power through this summer’s fighting season. Some of the troops that leave in July will be combat troops but commanders hope to minimize the impact by culling support staff as well.

In addition to U.S. forces, there are more than 40,000 international troops in Afghanistan, some of whom could also begin pulling out this summer, officials said.

Mr. Obama set the July deadline in December 2009 as he announced the surge of an additional 30,000 forces, in an effort to reassure Democrats skeptical of the war that even as he was building up troops in Afghanistan he wasn’t signing off on an endless conflict.

Military officials believe the White House doesn’t want a precipitous drawdown that would undercut U.S. gains in southern Afghanistan, a traditional stronghold of the Taliban, whose top leadership in Pakistan have had longstanding ties to bin Laden and his terror organization.

Outgoing Defense Secretary Robert Gates has said bin Laden’s death could be a “game-changer” in Afghanistan. U.S. officials hope that the weakening of al Qaeda might make their Taliban allies more receptive to a negotiated settlement, though they say it could take six months or longer to know what impact bin Laden’s death will have on the fighting.So far, the Taliban have appeared undeterred, and this weekend launched a two-day assault on the southern city of Kandahar in what the insurgents billed as the premiere of their spring offensive.

“The president has made no decision about the scope and pace of the drawdown that will begin in July, nor has he received any recommendation,” said Shawn Turner, spokesman for the president’s National Security Council, when asked about possible plans for a drawdown. “Any speculation is therefore completely premature and says nothing about the decision that the president will ultimately make.”

Rear Adm. Hal Pittman, senior spokesman for U.S. and NATO forces in Afghanistan, said Gen. Petraeus “has not finalized his thinking on the issue, nor shared it even with those who have supported the analysis which he, alone, will convey to the chain of command.”

Administration officials said Mr. Obama wants to show the initial drawdown is being accompanied by signs of progress in reconciliation efforts.

At the same time, advocates of a faster withdrawal could use bin Laden’s death as a rationale for demanding a bigger reduction than military staffers are now proposing.

“You will have a camp in the White House that will say, ‘With bin Laden gone, al Qaeda can’t go back into Afghanistan’,” a senior U.S. official said.

Under the staff proposals, units would mainly be withdrawn as their rotations in the war zone come to an end. Military officers are looking to achieve much of the reductions by sending home what they consider to be nonessential personnel and those who could do their jobs outside Afghanistan.

Military officers have been drafting proposals that include draw-down ranges, giving commanders greater flexibility in choosing how quickly to pull out.

Commanders want to preserve combat strength on the battlefield, and they are looking for ways to thin out headquarters’ staff and maintenance personnel while preserving as many infantry troops and trainers as possible.

Mr. Obama’s promise of a “significant” withdrawal from Afghanistan has fueled tensions between the White House and the Pentagon. Though military officials worry a rapid withdrawal of forces could undercut hard-won battlefield gains, they don’t want to be seen as pushing their agenda on the civilian leadership. White House officials, in turn, are wary of what they see as lobbying efforts by military commanders…..MORE HERE