U.S. Sen. Chuck Hagel writes in a new book that the United States needs independent leadership and possibly another political party, while suggesting the war in Iraq might be remembered as one of the five biggest blunders in history.

"In the current impasse, an independent candidate for the presidency, or a bipartisan unity ticket ... could be appealing to Americans," Hagel writes.

The Nebraska Republican, who announced last year he wouldn't seek a third term or the GOP presidential nomination, had been widely mentioned as a running mate on an independent ticket with New York Mayor Michael Bloomberg. Bloomberg said last month he wouldn't run.

"America: Our Next Chapter" is set to hit bookstore shelves March 25. The Associated Press obtained an advance copy from the publisher.

Hagel said despite holding one of the Senate's strongest records of support for President Bush, his standing as a Republican has been called into question because of his opposition to what he deems "a reckless foreign policy ... that is divorced from a strategic context."

Hagel, who's been a harsh critic of the war since 2003, blasts the Bush administration's handling of the war, writing that the invasion was "the triumph of the so-called neoconservative ideology, as well as Bush administration arrogance and incompetence."

The Vietnam veteran said he had hoped the lessons of Vietnam would give the nation's leaders perspective before troops were sent to Iraq.

"To the astonishment of those of us who lived through the agony of Vietnam, these lessons were ignored in the run-up to the Iraq War," he writes.

Hagel said Vice President Dick Cheney and others "cherry-picked intelligence" and used fear to intensify "war sloganeering."

During visits to the Middle East in December 2002, Hagel said, Israel's top security officials asked, "Do you really understand what you are getting yourselves into?"

Hagel said Bush personally assured him that he would exhaust diplomatic avenues before committing troops to Iraq. The senator said he voted for the war resolution based on those assurances, but said he regrets the vote because it's now clear that lawmakers were presented with lies and wishful thinking.

Last year, Hagel was the only member of his party on the Senate Foreign Relations Committee to support a nonbinding measure critical of President Bush's decision to dispatch an additional 30,000 troops to Iraq.

"There is no strategy. This is a pingpong game with American lives," Hagel said at the time.

Hagel lists his Nebraska Democratic counterpart, U.S. Sen. Ben Nelson, and the Republican presidential nominee, John McCain, among independent-thinking colleagues.

Democratic presidential candidate Barack Obama's name comes up in a chapter about Iran, in which Hagel calls for direct bilateral talks between Iran and the United States. Hagel writes about nuclear nonproliferation legislation he and Obama introduced last summer.

Obama has said he would be willing to negotiate with leaders of Iran and other unfriendly nations in the first year of his presidency.

Hagel warns against ignoring Iran's nuclear threats, calling it dangerously simplistic, and writes that "just labeling Iran as part of the 'axis of evil' and leaving it at that is dangerously short-sighted."