WASHINGTON — President Obama’s decision to accept Gen. Stanley McChrystal’s resignation and draft his superior, Gen. David Petraeus, to lead the war in Afghanistan eliminates a source of friction, but it doesn’t address the problems plaguing U.S. policy there.

The change in command, Obama made clear Wednesday, is a change in personnel, not in a policy that’s hampered by, among other things, the absence of a political strategy, rising U.S. casualties, growing ethnic tensions, endemic political corruption, the administration’s July 2011 deadline for beginning a troop withdrawal and a stalled offensive in the country’s second-largest city, Kandahar.

Petraeus, the head of the U.S. Central Command, is the main architect of the current strategy, which borrows some elements from the surge of additional U.S. troops he championed in Iraq, and he was largely responsible for putting McChrystal in charge of executing it.

If Petraeus’s appointment has any immediate effect, it’s likely to be on the prickly relationships among the strong personalities in charge of the war, including U.S. Ambassador to Afghanistan Karl Eikenberry, special envoy Richard Holbrooke and Vice President Joe Biden, and with the U.S.’s NATO allies and the Pakistanis.

“I think there will be a lot more of a ‘let’s work together’ spirit with Petraeus in charge, said Joseph Collins, a professor at the National Defense University in Washington.

However, whatever comity Petraeus brings — with his stature as the counterinsurgency general who saved the war in Iraq and his political savvy — is likely to be tested by disagreements over policy and personnel, some of which McChrystal and his aides vented about in their exit interview with Rolling Stone magazine.

As McClatchy reported earlier this month, a number of U.S. and allied military, intelligence and diplomatic officials have been warning for months that the American strategy in Afghanistan is failing and complaining that no one at a high level in the Obama administration wants to hear their discouraging words.

Eikenberry, a former three-star general, said in a cable that was leaked as the administration was crafting its strategy that he opposed deploying additional troops, the cornerstone of the current strategy, because Afghan President Hamid Karzai wasn’t a reliable partner.

All the additional troops are expected to be in Afghanistan by the end of the summer, bringing the U.S. troop level to 105,000. There currently are 94,000 U.S. troops and 48,000 allied forces.

It remains to be seen whether Petraeus can persuade Eikenberry to embrace the strategy. If not, the next question will be whether America’s best-known general can convince Obama to replace the senior U.S. official in Afghanistan, who technically outranks Petraeus.

Despite his involvement in the administration’s review and crafting of its Afghan strategy, Petraeus has distanced himself from the July 2011 withdrawal deadline, which some military officers and others think has prompted Karzai, the Taliban, neighboring Pakistan and Iran and others to jockey for leverage in post-American Afghanistan rather than cooperate with the U.S.

“Petraeus might carry more credibility than McChrystal did in reassuring the Afghan government and the regional powers that the start of a U.S. military withdrawal doesn’t mean an end to continued U.S. engagement in Afghanistan,” said Ronald Neumann, who served as the U.S. ambassador to Afghanistan from 2005 to 2007.

“Otherwise, nothing changes,” he continued. “You had a good general before, and now you have a good general who is also appreciative of political considerations in Washington.”

“The July 11, 2011, policy is confusing,” Sen. Lindsey Graham, R-S.C., an Air Force colonel and military lawyer, said Wednesday. “It undercuts the war effort. It empowers our enemies. It confuses our friends. And I think it needs to be re-evaluated.”

“If the president says, ‘no matter what General Petraeus may recommend, we’re going to leave in July of 2011,’ we will lose this war,” Graham said.

As Graham suggested, there’s some daylight between Petraeus and the White House — and especially Vice President Joe Biden — on the withdrawal issue.

On Capitol Hill last week, one senator asked Petraeus if he supported a deadline, which is counter to standard counterinsurgency doctrine. Petraeus replied with a “qualified yes.”

Instead, he’s stressed that the pace of a withdrawal must be based on conditions, while Biden and other administration officials have called a July 2011 withdrawal certain.

Nor can Petraeus, who in Baghdad was notorious for browbeating the Iraqi government to take responsibility for its own country’s security, resolve the differences between the Taliban and a majority of the Afghan people or the growing disputes between the Karzai administration and leaders of Afghanistan’s minorities, both of which are confounding efforts to find a political resolution to the conflict.

Nazif Shahrani, an Indiana University anthropology professor who’s from northern Badakshan province, said it’s impossible to forge a compromise between the hard-line Islamic rule sought by the Taliban leaders, who reject democratic governance, and Afghanistan’s constitutional system with an elected president and parliament.

Karzai, a Pashtun, has used his position, Shahrani said, to funnel political and economic patronage to his relatives and other Pashtuns while gradually pushing out Tajik and other non-Pashtun leaders.

The resulting ethnic tensions have been growing as all sides consolidate their positions in anticipation of a U.S. withdrawal and as Karzai steps up peace overtures to the overwhelmingly Pashtun Taliban and allied Pashtun-dominated insurgent groups widely thought to be backed by neighboring Pakistan.

Indeed, some U.S. officials think that Pakistan has continued to provide sanctuary and support to some militant Islamic groups in an effort to counter what it fears could be growing Indian influence and ensure that a post-American Afghanistan is pro-Pakistan.

All these problems, along with a shortage of civilian personnel, the absence of a credible Afghan civilian government and difficulties training the Afghan military and police forces, have hampered the U.S.-led effort to free the southern Afghan city of Marjah from the Taliban’s grip.