With Admiral Michael Mullen scheduled to retire this September, the Obama Administration has been on a fast paced course to find a replacement for the chairman of the Joint Chiefs of Staff — the most powerful officer in the United States military.

Mullen is considered a holdover from the previous administration, when George W. Bush nominated him to head the Joint Chiefs during one of the most difficult phases of the wars in Afghanistan and Iraq. If Mullen served Bush well, his advice has been equally valuable to a president with little to no formal national-security experience.

After months of internal White House deliberations, President Obama and his National Security Council decided to tap Army General Martin E. Dempsey for the position, pending confirmation by the United States Senate.

Before Dempsey’s short tenure as Army Chief of Staff, he served as a commanding general in Iraq several times. In 2003-2004, as the insurgency in Iraq was picking up steam and violence against American troops was increasing, Dempsey was tasked by the Bush Administration to oversee a 20,000 men strong force in Baghdad, arguably the most violent Iraqi city during that time.

After inheriting that particularly tough job, Dempsey was promoted as the commander of the Multinational Security Transition Command in September 2005, a unit responsible for training and recruiting the Iraqi security forces. That job also proved to be an exceedingly difficult one, yet a major component of the counterinsurgency strategy that the United States adopted later in the war.

Dempsey has a long career in the Army, graduating from the United States Military Academy in 1974, just when the Vietnam War was drawing to a close. Soldiers, congressmen and fellow generals alike admire his leadership style, which was surely one of the reasons for the president nominated him for the job.

The interesting story behind his nomination is that he was not Barack Obama’s first choice. That honor went to General James Cartwright, who was the Vice Chairman of the Joint Chiefs and a man the Obama White House was comfortable in dealing with.

During the Afghanistan surge debate, Cartwright was Obama’s trusted advisor, providing the president with an alternative strategy outside the narrow recommendations provided by Mullen and defense secretary Robert Gates (an additional infusion of 40,000 troops). The fact that Cartwright was close to the president was important. He has had rough relationships with his generals in the past, peeking with the Rolling Stone controversy in which General Stanley McChrystal’s military staff (who then led the US/NATO command in Afghanistan) said some unflattering things about Obama’s civilian team.

Although Cartwright’s relationship with the president was admirable, it also appeared to be his Achilles’ heel. According to The Washington Post, Mullen and Gates lobbied against Cartwright for the chairmanship. Fearing that he was too intimate with the president and convinced that Cartwright persuaded Obama to refuse their requests for an additional troop surge in Afghanistan, Gates and Mullen teamed up behind the scenes to oppose his nomination. It worked. Dempsey is in, Cartwright is out.

The Obama White House now has a national-security team that they can truly call their own. Gates and Mullen, the two Bush holdouts, will both retire. General David Odierno, whose leadership was key to successful counterinsurgency operations in Iraq during 2007 and 2008, will take over as the Army Chief of Staff. David Petraeus, the other COIN superstar, is preparing for his new role as director of the CIA. And Leon Panetta, the current intelligence chief, is itching to lead the Pentagon once Gates retires.

The president clearly believes that it is far more effective to reset the national-security command before the 2012 presidential elections. With a deadly insurgency in Afghanistan, a lingering air conflict in Libya and a full withdrawal from Iraq still on the administration’s calendar, Dempsey, Odierno, and Panetta will only have a short time to fit into their new roles.