President Barack Obama has named Gen. Martin Dempsey, the relatively new Army chief of staff, to be the next chairman of the Joint Chiefs of Staff.

The term of current chairman Adm. Michael Mullen, ends in September. Mullen will retire.

Dempsey is an armor officer who graduated from the U.S. Military Academy in 1974, the same class as Gen. David Petraeus. Agence France-Press called Dempsey “an extrovert with an irreverent sense of humor and a penchant for singing in public.” His rendition of “New York, New York” is said to be a match for Frank Sinatra’s. He is also “battle hardened” and a “strategic visionary,” say some in Washington, and he is relatively free of political baggage – but Dempsey was not President Barack Obama’s first pick for the job.

Obama made three attempts to persuade JCS vice chairman Gen. James Cartwright to accept the job, and once told Cartwright, “You’re my man.” But Cartwright argued against a surge of U.S. troops in Afghanistan, calling for a much smaller increase in troop levels in a way that rankled outgoing Defense Secretary Robert Gates and chairman Adm. Michael Mullen. Cartwright had other baggage, too, and would have faced stiff Republican opposition in Senate hearings. Dempsey is expected to have no difficulty winning the consent of the Senate.

In announcing the appointment, Obama called Dempsey “one of our nation’s most respected and combat-tested generals.”

Obama named Adm. James A. “Sandy” Winnefeld, Jr., the head of U.S. Northern Command and of the North American Aerospace Defense Command, to replace Cartwright as vice chairman of the JCS. Like Cartwright, Winnefeld is a naval aviator. He was an F-14 Tomcat pilot and used the callsign “Jaws.” Like Mullen, Winnefeld is often cited as evidence of a popular Washington theory that the Navy is producing the best officers nowadays: naval officers were chosen in recent years for several key combatant commander positions. Air Force Chief of Staff Gen. Norton Schwartz had been considered a candidate for the vice chairman job. Asked about the changes when they were pending, Schwartz said he would not be able to comment.

The selection of Dempsey in itself is unusual because he took over as the Army’s service branch chief only on April 11. Gen. Ray Odierno, a veteran commander of U.S. forces in Afghanistan, is the administration’s choice to be the next Army chief of staff.

Dempsey served as commander of the 1st Armored Division in Baghdad in 2003, and then helped train Iraqi security forces in a subsequent tour of duty in Iraq. If confirmed by the Senate, Dempsey would move to his new post Oct. 1 and would become Obama’s senior military adviser, overseeing the drawdown of troops in Iraq and Afghanistan. The administration is committed to trimming $400 billion in defense spending by 2023; Dempsey would work daily with incoming Defense Secretary Leon Panetta, who also still needs to be confirmed by the Senate, to establish priorities for spending cuts.