Hamilton and Panetta said Baker, who served as secretary of State under former President George H.W. Bush, is consulting with senior administration officials about the possibility of compiling another assessment of the war. The group published its first set of findings after the 2006 elections.

Norm Ornstein, a government scholar at the American Enterprise Institute, said that the Bush administration would likely prefer not to have the Iraq Study Group raising new attention to the war in Iraq now that the issue has slid from the center of media and public attention.

“I think the administration doesn’t want to be reminded that the Iraq Study Group issued a report they snubbed for a long time before belatedly embracing it,” he said. He added that another investigation may remind Americans that the war has done little to establish real stability in Iraq.

Bringing the group back to life might also remind many Americans that the Bush administration has failed to achieve a central recommendation issued in 2006: that the U.S. military should cede its active combat role to the Iraqi military and police.

One senior Democratic aide said the White House has held up a new probe by the study committee, noting that Baker’s talks with the administration have been cited as a reason for delay.

“It appears that this process has hit a bottleneck at the White House. Congress’s intent was clear,” said the aide.

Ian Larsen, a spokesman for the U.S. Institute of Peace, also said Baker was the reason for the hold- up.

“At this point, we are waiting for Baker’s word as to whether he wants to be part of a reconvened study group,” said Larsen. “Until Baker gives us the thumbs-up or the thumbs down, we’re in a holding pattern.”

But Hamilton said it is unfair to claim that Baker is the sole reason.

“I think it is more involved than that,” said Hamilton, but did not say who might be to blame.

Democrats on the Hill have reasons to prefer that the study group remain inactive.