Democratic presidential hopeful Wesley Clark (search) says a book by former Treasury Secretary Paul O'Neill (search) vindicates what he has said all along about the U.S. invasion of Iraq.

While rallying campaign volunteers Sunday at his Manchester headquarters, Clark praised O'Neill for "The Price of Loyalty," which contends the United States began the war on Iraq (search) just days after President Bush took office -- more than two years before the start of the overthrow of Saddam Hussein.

O'Neill was fired by Bush in December 2002.

Clark first met O'Neill when Clark worked at the White House during the Ford administration, and calls him a man with "100 percent, rock-solid commonsense judgment."

"When he writes that the Bush administration is planning and exchanging documents on how to go to war with Iraq as soon as they took office, that just confirms my worst suspicions about this administration," Clark said.

In Clark's book, "Winning Modern War", which came out in November, the retired Army general traced the plotting of the war in Iraq back to 1996, when he says a group left over from the first Bush administration recommended that Israel focus on removing Saddam from power.

Clark goes on to write that in 1998, the group of 20, which included Donald H. Rumsfeld and Paul Wolfowitz, now Defense Secretary and Deputy Defense Secretary, respectively, wrote a letter to President Clinton, asking him to "aim, above all, at the removal of Saddam Hussein's regime from power."

"We went to a war in Iraq we didn't have to go to," Clark told a group of supporters. "I'm calling on the Congress of the United States to fully investigate exactly why this country went to a war it didn't have to fight."

Clark said he was in the Pentagon immediately after the Sept. 11 terror attacks, and heard officials joking that, "'if Saddam didn't do it, he should have, because if he didn't, we're going to get him anyway.'"