If Gen. David Petraeus is confirmed as commander of U.S. Central Command, his broader responsibilities may force him to reconsider his thinking about U.S. commitments in Iraq in order to properly resource the U.S. effort in Afghanistan, say some analysts and military observers.

In his new role as the senior military officer for U.S. forces across the Middle East and Central Asia, Petraeus "will have to balance three competing demands: the fighting in Iraq, the fighting in Afghanistan and the strain on the force," according to Lt. Col. John Nagl, one of the U.S. Army's acknowledged counterinsurgency experts.

Nagl, a former student of Petraeus' who worked with him on the U.S. Army's counterinsurgency strategy, spoke in a brief interview with United Press International.

There is widespread agreement in military circles not only that the current multiple 15-month combat deployments in Iraq are stretching the Army to the point of exhaustion, but also that the U.S. effort in Afghanistan is under-resourced, with not enough troops on the ground and a consequent over-reliance on air power.

The Bush administration's "strategy has been to fully resource Iraq and make do in Afghanistan with what's left," said Michele Flournoy, a Clinton-era senior defense department official who now heads the non-partisan Center for a New American Security.

She says Petraeus will now have to decide whether to try and change that. In his new job, "he will have to recommend to the president how best to balance risk and distribute resources across Iraq and Afghanistan," said Flournoy.

Petraeus has been asked by lawmakers before about the best way to allocate troops between the two theaters, noted Rand Beers, a White House national security official who served Presidents Clinton and George W. Bush.

Beers now heads the progressive National Security Network of former officials and experts, a group that has been a consistent critic of administration policy in Iraq.

"Up to this point, he has legitimately sidestepped the question of how to balance our commitments in Iraq and Afghanistan," said Beers.

"He quite rightly said, 'It's not my job.' Well, it is now."

Many regional experts believe that al-Qaida's safe haven on the Afghanistan-Pakistan border represents a more direct threat to the United States than the group's insurgency in Iraq, where it is tied down by U.S. forces and their Iraqi allies. Training camps in the border region have been linked to European-born extremists involved in terror plots like the July 7, 2005, attacks in London. At least one, broken up by British authorities in August 2006, targeted the United States.

"That threat is now (going to be) his responsibility," said Beers.

One of the key elements of any successful counterinsurgency strategy is enough troops to clear and hold territory, and Flournoy says that will be something Petraeus will have to address up front.

"One of the first things in his inbox will be a request" from the new U.S. commander in Afghanistan "for two to three more army brigades" to be deployed there.

"They are just not available right now," she said, because of U.S. commitments in Iraq.

By deferring to Petraeus to set troop levels in Iraq, she said President Bush had "abrogated part of his responsibility as commander in chief."

"It is the president's job to balance strategic risk across the globe," she said, adding that a field commander could not be expected to weigh the resources he needed for his own operations against the importance of the job they might do elsewhere.

"'I'll do whatever the field commander tells me' is great political rhetoric but a lousy way to exercise presidential command," she said.

Petraeus would also have to factor in the impact of the Iraq commitment on the U.S. ability to respond to "other possible conflicts in a volatile region."

"It will broaden his perspective," she said, and "should give him a fundamentally rebalanced set of priorities," she said of his new role.

"The good news is, he has shown impressive generalship in Iraq and he is a true strategic thinker �� exceptional at working through complex problems."

"I think he will step up to the challenge," she said.

Nagl agrees Petraeus is up to the job.

"In my opinion he will square that circle as well as any human could," he said.

Others were more skeptical. Lawrence Korb, a Reagan-era senior defense official now at the liberal-leaning Center for American Progress, questioned whether Petraeus could "objectively assess priorities as the overall commander" of both theaters.

"If history is any guide," Korb wrote in a statement, Petraeus "will have difficulty remaining impartial," charging he had "painted an overly optimistic picture of the progress that the Iraqi Security Forces were making" in a newspaper op-ed "a month before the 2004 election."

Korb also pointed out that, since regional commanders are appointed for a three-year term, his confirmation would "effectively �� lock in" Petraeus as the head of CENTCOM "for the next president, whomever he or she may be, regardless of their objectives in Iraq."

Flournoy took a different tack on that issue, saying that it was "smart to put in a team" of Petraeus and Gen. Raymond Odierno -- his current deputy, who would be promoted behind him -- before the election, and subsequent transition, got under way.

"There's an element of risk associated with managing a war during that transition," she said, and it would be good to have "a point of continuity as the political process sorts itself out."