Retired Marine Gen. Anthony C. Zinni, former U.S. commander in the Middle East, charges in a book to be published today that "everybody in the military knew" that the Bush administration's plan for Iraq consisted of only half the troops that were needed, and says that country is now "a powder keg" that could break apart into warring regions.

Zinni has been a critic of the Iraq war since before the invasion and served briefly as a special envoy for President Bush. He wrote that he was moved to speak out by "false rationales presented as a justification; a flawed strategy; lack of planning; the unnecessary alienation of our allies; the underestimation of the task; the unnecessary distraction from real threats; and the unbearable strain dumped on our overstretched military."

"In the lead-up to the Iraq war and its later conduct, I saw, at a minimum, true dereliction, negligence, and irresponsibility; at worst, lying, incompetence, and corruption," he wrote. " . . . If there is a center that can hold this mess together, I don't know what it is. Civil war could break out at any time. Resources are needed; a strategy is needed; and a plan is needed."

The harsh new critique is being released just as Bush heads to the U.S. Army War College in Carlisle Barracks, Pa., to present his latest strategy for Iraq in a prime-time address at 8 p.m. today. Zinni is hitting the interview circuit at a time when Republican lawmakers have turned sharply pessimistic about the situation in Iraq and the White House continues trying to restore confidence in its handling of the war despite falling poll numbers and continuing revelations about brutality against detainees in Iraq.

The book, "Battle Ready," is by novelist Tom Clancy, with Zinni and Tony Koltz. Zinni was U.S. special envoy to the Middle East for Secretary of State Colin L. Powell from November 2002 to March 2003. In several interviews and statements at the time, Bush mentioned Zinni's presence in the region as one reason for his optimism about the peace process and said he was looking forward to his recommendations. Referring to himself and Vice President Cheney, Bush said during an exchange with reporters in the Oval Office, "We both trust General Zinni."

A passage written by Zinni voiced support for the views of retired Gen. Eric K. Shinseki, the former Army chief of staff, whose estimate that several hundred thousand troops would be needed in postwar Iraq was dismissed by the administration as wildly off the mark. "Recently, the Army chief of staff testified that we would need 300,000 troops to pacify Iraq," Zinni wrote. "Everybody in the military knew he was right. But the party line down from the Pentagon decreed that the number was half that, and he was pilloried."

Zinni, 60, appeared last night on CBS's "60 Minutes" and said that staying the course in Iraq is not feasible. "The course is headed over Niagara Falls," he said. "I think it's time to change course a little bit or at least hold somebody responsible for putting you on this course." He said the current situation is the product of "poor strategic thinking" combined with "poor operational planning and execution on the ground."

Zinni was one of the earliest and most outspoken critics of the war and remains highly regarded in the military. He was commander of the U.S. Central Command from 1997 to 2000. He wrote that when he left, he had a preliminary plan for attacking Iraq. "I'm not sure where it went after I left. As far as I can tell, the plan was pigeonholed," he said.

His successor, Gen. Tommy R. Franks, prosecuted the war past the fall of Baghdad and is now retired. Discussing the Iraq war with The Washington Post in December, Zinni said he believed that "the American people were conned into this."