Washington ? Bitter divisions over the Iraq war, particularly on Capitol Hill, led the Bush administration to change course and replace Gen. Peter Pace as chairman of the Joint Chiefs of Staff, a grim Defense Secretary Robert Gates said Friday.

Gates said that despite earlier plans to recommend Pace for a second two-year term as chairman, he instead was recommending Adm. Mike Mullen, currently chief of naval operations, to take over when Pace’s term expires Sept. 30. President Bush accepted the recommendation.

“I think that the events of the last several months have simply created an environment in which I think there would be a confirmation process that would not be in the best interests of the country,” Gates said. “I wish it were not necessary to make a decision like this. But I think it’s a realistic appraisal of where we are.”

Bush praised Pace, saying he has “relied on his unvarnished military judgment, and I value his candor, his integrity, and his friendship.”

“Pete’s job has been to help ensure that America’s military forces are prepared to meet the threats of this new century,” Bush said in a statement issued in Rome, where he is visiting. “This is a difficult task in a time of peace. Pete Pace has done it in a time of war – and he has done it superbly.”

Gates said he had been told by Republican and Democratic senators that a confirmation hearing for Pace would be a “backward-looking and very contentious process.”

Sen. Carl Levin, D-Mich., acknowledged such advice, saying he had gathered views from a broad range of senators. “I found that the views of many senators reflected my own,” and confirmation would have focused on the past four years of war, he said.

A spokesman for Sen. Hillary Rodham Clinton, D-N.Y., said she, too, believed it would have been a difficult renomination.

“When it comes to Iraq it’s not enough for President Bush to change the cast, he must also change their script,” said the spokesman, Philippe Reines.

Mullen has long been eyed for a promotion, and Gates praised him on Friday as having the “vision, strategic insight and integrity to lead America’s armed forces.”