WASHINGTON (AP) _ President George W. Bush is promoting his top Iraq commander, Army Gen. David Petraeus, and replacing him with the general’s recent deputy, keeping the United States on its war course and handing the next president a pair of combat-tested commanders who have relentlessly defended Bush’s strategies.

Bush will nominate Petraeus to replace Navy Adm. William J. Fallon as chief of U.S. Central Command, Defense Secretary Robert Gates announced Wednesday. The Petraeus choice represents a return to the more common practice of making it an Army slot.

Petraeus would be succeeded at a pivotal time in Baghdad by Army Lt. Gen. Ray Odierno, who was the No. 2 commander in Iraq for 15 months under Petraeus. He has been credited by many with deftly managing security gains that Petraeus told Congress this month have opened a pathway for potential political progress in the country.

Gates said he hoped the Senate would act on both nominations by next month and expected Petraeus to switch to the Central Command job, which is based in Florida, by September or October.

That is the point at which Petraeus is likely to make an initial recommendation to Gates and to Bush on whether conditions in Iraq are stable enough to permit a further reduction in U.S. troop levels.

The United States has about 160,000 troops in Iraq and about 28,000 in Afghanistan. The strain of those wars has taken a heavy toll on U.S. ground forces.

Among the politically sensitive questions Petraeus would face as head of Central Command is whether the military focus on Iraq is limiting what U.S. and allied forces can accomplish in Afghanistan. And he would be pressed on the matter of using military force against Iran.

At a Pentagon news conference, Gates said he did not foresee that the new lineup at Central Command and in Iraq would mean any changes in the way the United States is approaching the issue of Iranian influence in Iraq. Both Petraeus and Odierno have accused Iran of aiding rebels opposing U.S. troops.

Petraeus will face broader aspects of the Iran issue if he is confirmed as Fallon’s replacement. A number of U.S. officials, including Adm. Michael Mullen, chairman of the Joint Chiefs of Staff, have asserted that Iran also is supplying arms or otherwise supporting the Taliban rebels in Afghanistan.

Early this week, Gates said that while war with Iran would be “disastrous on a number of levels,” the military option cannot be abandoned so long as the Iranians remain a potential nuclear threat.

Asked why he had recommended Odierno, Gates said, “General Odierno is known recently to the Iraqi leadership, he’s known to the Iraqi generals, he is known to our own people, he has current experience,” and so the odds of a smooth transition in Baghdad “are better with him than with anybody else I could identify.”