If confirmed, Gen. Joseph Dunford will become the fifth top allied commander in Afghanistan in five years. (THIERRY CHARLIER/AFP/GETTY IMAGES)

A Marine general with extensive combat experience in Iraq who sped up the ranks upon returning to the Pentagon has been nominated by President Obama to lead U.S. and NATO forces in Afghanistan.

Gen. Joseph F. Dunford, who has not served in Afghanistan, would replace a fellow Marine four-star general, John R. Allen, who has been selected as the next supreme allied commander in Europe. Both moves, which are expected to occur early next year, require confirmation by the Senate and the North Atlantic Council, the principal decision-making body within NATO.

Speaking before a meeting of NATO defense ministers in Brussels, Defense Secretary Leon E. Panetta called Dunford “an exceptionally gifted strategic leader.”

If confirmed, Dunford will preside over the war in Afghanistan at a challenging juncture. Although allied forces have improved security in some parts of the country, the Taliban insurgency remains resilient. Efforts by the U.S. military and its NATO partners to train the Afghan army and police have been hampered by a wave of attacks on allied forces by members of the Afghan security forces, many of which are the result of Taliban infiltration.

Dunford, who would be the fifth top allied commander in Afghanistan in five years, almost certainly would have to deal with a further reduction of U.S. and NATO forces. The specific number of U.S. troops to be withdrawn next year will depend, in part, on who wins the presidential election next month, but military leaders are expecting a substantial drawdown to meet U.S. and NATO commitments to end conventional combat operations by the close of 2014. The United States has about 68,000 combat troops in Afghanistan.

If confirmed, Obama said in a statement, Dunford “will lead our forces through key milestones in our effort that will allow us to bring the war to a close responsibly as Afghanistan takes full responsibility for its security.”

Dunford is the assistant commandant of the Marine Corps. In 2003, he led a Marine regiment in the invasion of Iraq. He later served as a chief of staff and as an assistant commander of the 1st Marine Division in Iraq.

After serving as the Corps’s director of operations, he vaulted from a one-star brigadier general to a three-star lieutenant general in less than three months — a highly unusual move — when he was selected for a senior Marine Corps job by then-Defense Secretary Robert M. Gates. A year later, in May 2009, he was given command of the 1st Marine Expeditionary Force, but in less than 12 months, he was promoted again — to the assistant commandant post.

The change of top commanders in Kabul is not the result of any dissatisfaction with Allen at the White House or Pentagon. Allen, who arrived in Kabul in July 2011, has had a grueling schedule and often sleeps less than four hours a night. The move to Europe is seen as a promotion.

The selection of another Marine general to lead the war had led to grumbling among some top Army officers, who wanted one of their own, Gen. David M. Rodriguez, to get the assignment. But senior White House and Defense Department officials concluded that Rodriguez, who has spent more than three years in Afghanistan in senior command roles, lacked Dunford’s strategic acumen. Rodriguez is expected to be nominated to lead the military’s Africa Command next year, according to military officials.