Promoting his latest book from the “Commanders” series, Tom Clancy, who co-authored “Battle Ready” with former Marine Gen. Anthony Zinni, said he once “almost came to blows” with Pentagon adviser Richard Perle.

Both authors are critics of the Iraq war.

Zinni has openly attacked the war, but Clancy reluctantly acknowledged his own concerns. He declined repeatedly to comment on the war, before saying that it lacked a “casus belli,” or suitable provocation.

“It troubles me greatly to say that, because I’ve met President Bush,” Clancy said. “He’s a good guy. … I think he’s well-grounded, both morally and philosophically. But good men make mistakes.”

In discussing the Iraq war, both Clancy and Zinni singled out the Department of Defense for criticism. Clancy recalled a prewar encounter in Washington during which he “almost came to blows” with Richard Perle, a Pentagon adviser at the time and a longtime advocate of the invasion.

“He was saying how (Secretary of State) Colin Powell was being a wuss because he was overly concerned with the lives of the troops,” Clancy said. “And I said, ‘Look …, he’s supposed to think that way!’ And Perle didn’t agree with me on that. People like that worry me.”

Neither Clancy or Zinni would commit to supporting President Bush in the Fall.