WASHINGTON — As Colin Powell's right-hand man at the State Department, Col. Larry Wilkerson seethed quietly during President Bush's first term. Wilkerson made up for lost time Wednesday.

He said the vice president and the secretary of defense created a "Cheney-Rumsfeld cabal" that hijacked U.S. foreign policy. He said of former defense undersecretary Douglas Feith: "Seldom in my life have I met a dumber man."

Addressing scholars, journalists and others at the New America Foundation, Wilkerson accused Bush of "cowboyism" and said Condoleezza Rice was "extremely weak." Of American diplomacy, he fretted, "I'm not sure the State Department even exists anymore."

And how about Karen Hughes' efforts to boost the country's image abroad? "It's hard to sell [manure]," Wilkerson said, quoting an Egyptian friend.

The man who was chief of staff at the State Department until early this year continued: "If you're unilaterally declaring Kyoto dead, if you're declaring the Geneva Conventions not operative, if you're doing a host of things that the world doesn't agree with you on and you're doing it blatantly and in their face, without grace, then you've got to pay the consequences."

With Bush's approval ratings below 40 percent, the administration's vaunted loyalty and party discipline are suffering.

David Frum, a former White House speechwriter, is campaigning against confirmation of Harriet Miers to the Supreme Court. Bruce Bartlett, who worked for the president's father, was fired by a think tank this week because he is publishing a book titled "Impostor: How George W. Bush Bankrupted America and Betrayed the Reagan Legacy."

And, on Capitol Hill on Wednesday, Republicans joined in criticizing the administration about Iraq. When Rice said at a hearing that "we have made significant progress" in Iraq, Sen. Lincoln Chafee, R-R.I., replied: "Well, we all wish that were true, but we can't kid ourselves, either."

Wilkerson adds a new dimension to the criticism. A 31-year military veteran and former director of the Marine Corps War College, he worked for Powell in the public and private sectors for much of the past 16 years, and he often was described by colleagues as the man who would say what Powell was thinking but was too discreet to say.

Wilkerson's beef with the administration, for the most part, was not ideological. He argues that U.S. forces must remain in Iraq, and he describes George H.W. Bush as "one of the finest presidents we've ever had."

Rather, the colonel objected to the administration's secrecy, which he said allowed Dick Cheney, Donald Rumsfeld and others to subvert the foreign-policy apparatus that has been in place since 1947.

"What I saw was a cabal between the vice president of the United States, Richard Cheney, and the secretary of defense, Donald Rumsfeld," he said. By cutting out the bureaucracy that had to carry out those decisions, "we have courted disaster in Iraq, in North Korea, in Iran, and generally with regard to domestic crises like Katrina."

The colonel said his old boss is not pleased with his decision to go public with his criticism. Powell, he said, "is the world's most loyal soldier." Wilkerson said he admired that, but he took a different view of loyalty: not to the administration, but to the country.