US Defense Secretary Robert Gates said Friday he was replacing General Peter Pace as chairman of the Joint Chiefs of Staff to avoid a divisive showdown in Congress focusing on the Iraq war.
The surprise shakeup removes a general who has been at the center of US military decision-making for the past six years, from the war in Afghanistan to the US-led invasion of Iraq.
"I am disappointed that circumstances make this kind of a decision necessary," Gates said of the loss of Pace, who has held the country's top military post since September 2005.
The moves comes amid persistent difficulties in Iraq and sharpening political tensions at home with Congress already gearing up to receive a key progress report from US military commanders on the Iraq war in September.
Gates said he had intended to name Pace to a second two-year term as chairman in September, but changed his mind after consulting members of Congress, who also already have an eye on the 2008 presidential polls.
"I have decided that at this moment in our history, the nation, our men and women in uniform and General Pace himself would not be well served by a divisive ordeal in selecting the next chairman of the Joint Chiefs of Staff," he told reporters.
Pace as chairman of the Joint Chiefs of Staff is the chief military adviser to US President George W. Bush and the most senior US military officer.
"I'm told the president reluctantly agreed because he has the highest regard for General Pace," said White House spokeswoman Dana Perino.
In deciding to replace Pace with Admiral Michael Mullen, who is currently the chief of naval operations, Gates also had to replace Admiral Edmund Giambastiani as vice chairman so that the top two military positions would not both be held by naval officers.
Giambastiani will be replaced by Marine General James Cartwright, currently the head of the US Strategic Command, which is responsible for US strategic nuclear forces.
Bush later said in a statement he was "pleased to accept" his defense secretary's recommendation to have Pace replaced by Mullen, whom he said "will make a superb Chairman of the Joint Chiefs of Staff," and Mullen by Cartwright as vice chairman.
Bush praised Pace for serving his nation "with great distinction for forty years," and for ensuring US "military forces are prepared to meet the threats of this new century."
Gates insisted that his decision was no reflection on either Pace's or Gambastiani's performance, only of the political realities of getting them confirmed to a second term.
He said he had spoken with Democratic and Republican senators over the past several weeks and came away convinced that "there was the very real prospect the process would be quite contentious."
Both officers were closely associated with former defense secretary Donald Rumsfeld, leading analysts to conclude Gates is clearing the decks to make way for officers with less baggage and a fresh perspective.
"Almost everybody who is getting a top job in the Pentagon now is in the mold of Bob Gates, meaning they are not ideological and they are oriented more to management excellent than to visionary ideas," said Loren Thompson, director of the Lexington Institute, a research group.
Pace will step down in September after a distinguished 40 year career in the marines that has ended under the cloud of a protracted and unpopular war.
"Bottom line is Pace was vice chairman of the Joint Chiefs of Staff when we prepared the worst war plan in the last 35 years in this country, and probably one of the two or three worst in our nation's history," said Michael O'Hanlon, a military analyst at the Brookings Institution.
Pace's military career began in 1968 as the leader of a rifle platoon in Vietnam, another divisive and unpopular war.
He commanded US troops in Latin America, served as director of the Joint Staff, and was deputy commander of US forces in Somalia during an ill-fated intervention in the early 1990s.
He was named vice chairman of the Joint Chiefs of Staff just weeks after the September 11, 2001 attacks on the United States, becoming the first marine in history to hold the post.
Mullen, a surface warfare commander who studied at Harvard Business School, served as commander of US naval forces in Europe and was in charge of NATO operations in the Balkans, Iraq and the Mediterannean.
He became the chief of naval operations in July, 2005.
Gates called him "a very smart strategic thinker."