In early 1998, the chairman of the Joint Chiefs of Staff, Hugh Shelton, sent all 17 of his four-star generals a book called "Dereliction of Duty." Then he summoned them to a breakfast at which the author, a young Army major named H.R. McMaster, described how Lyndon B. Johnson's top generals let the president bog us down in Vietnam without voicing their strong reservations.

One of the generals at the breakfast, Tony Zinni, who was then head of Central Command, recalled for me the chairman's firm words. "This will never happen again," Shelton said.

But despite internal grumbling about the administration's strategy for the Iraq war, most top brass have stayed silent. Now, some retired officers are speaking up.

Zinni is one of several retired generals who recently have decried the failure of senior brass to criticize the huge mistakes by Pentagon and White House leaders that led to the miring of America in Iraq. All have called upon Secretary of Defense Donald Rumsfeld to resign.

What is so important about these critiques is that they not only confirm the egregious lack of Pentagon planning for the postwar, they also underline how the same blindness is undercutting prospects for stabilizing Iraq.

Retired Lt. Gen. Gregory Newbold, a three-star Marine who was the top Pentagon operations officer before the invasion, wrote last week that the decision to invade Iraq "was done with a casualness and swagger that are the special province of those who have never had to execute these missions — or bury the results."

Paul D. Eaton, a retired Army major general who was in charge of training the Iraqi military from 2003 to 2004, accused Rumsfeld of "ignoring the advice of seasoned officers and denying subordinates any chance for input."

Zinni, who retired before the Iraq war, recalls that any questions about postwar planning were unwelcome to Rumsfeld: "The military was told not to worry about Phase IV" (the postwar).

Senior military officials had developed a contingency plan in the 1990s in case of an Iraq invasion, calling for 380,000 to 500,000 troops. Rumsfeld said the plan was old and stale; Zinni says it was "living, breathing and dynamic," and was updated yearly. In 2003, the top Army general, Eric Shinseki, said several hundred thousand troops would be needed for a postwar Iraq, but he was humiliated by Rumsfeld, sending a clear message to other military critics to shut up.

Zinni was worried before the Iraq war that the invasion would lead to chaos. (His concerns about promoting Mideast stability are laid out in his new book, "The Battle for Peace.") He believed that if you break a highly authoritarian state, a period of occupation would be required to rebuild it. Just before the war, he asked in testimony before the Senate Foreign Relations Committee, "Do we understand what we will need to do?"

But the civilian leadership of the Pentagon was wholly unprepared for occupation and believed that Iraq would quickly spring back to order. Initial plans called for a drawdown to 30,000 U.S. troops within three months of the invasion. This resistance to reality is why the three generals believe Rumsfeld must go.

Zinni pointed out that the defense secretary even rejected Condoleezza Rice's claim that "tactical" mistakes had been made in Iraq (though Zinni thinks the mistakes were strategic). So long as Rumsfeld stays, Zinni says, "we are constantly defending the past, which limits the ability to move ahead. We are not as free to make changes, to accept new ideas."

One prime example is the Pentagon's new Quadrennial Defense Review, which seems to draw no lessons from Iraq failures. Iraq has shown that any effort to help rebuild failed states calls for more, and better trained, ground forces. Many senior officers are bitter that the Pentagon has not learned this lesson. Instead, Rumsfeld has called for a traditional goody bag of expensive heavy-weapons programs.

The message from the military on the ground doesn't seem to be reaching the Pentagon, either. Zinni says "many small-unit commanders are discouraged" at the lack of an overall strategy that builds on their work at local levels. "They go back for a second tour and can't believe how far things have sunk," he says.

That may turn out to be the case for now-Col. McMaster, the author of "Dereliction of Duty," who was praised by President Bush for his work in wresting the town of Tal Afar from al-Qaida control. McMaster's Third Armored Cavalry was moved out; military sources say insurgents are already infiltrating back into Tal Afar. Let's hope the colonel doesn't feel compelled someday to write a second book.