The president fielded questions from the public for nearly an hour at Cleveland's City Club, a forum known for its tough interrogations of world leaders, reports the Associated Press.
In light of there having been no weapons of mass destruction, Bush was asked how Iraq was determined to have been enough of a threat three years ago to launch an invasion, in contrast to nuclear-ambitious Iran today.
"One difference was that, in Iraq, there was a series of unanimous (U.N. Security Council) resolutions that basically held the Iraqi government to account, which Saddam Hussein ignored," Bush said. Still, he said Iran was a concern, on the question of nuclear weapons and on its role in Iraq.
Another man inquired how the president could restore confidence in U.S. leadership after several reasons for going to war with Iraq later proved false.
"Like you, I mean, I asked that very same question: Where'd we go wrong on intelligence?" Bush replied. He said he was working to improve intelligence gathering because "the credibility of our country is essential."
Also political on Monday was a "Bring 'Em Home Now!" concert in New York starring Michael Stipe, Susan Sarandon, Moby and others who were marking the third anniversary of the invasion.
"I was raised by peace activists," Moby announced to the crowd at Manhattan's Hammerstein Ballroom from a stage flanked by two oversized peace symbols. He then accompanied Laura Dawn in a rendition of Buffalo Springfield's Vietnam-era song, "For What It's Worth."
The anti-war concert sold 3,000 tickets, organizers said. Profits from the sales will go to anti-war groups including Gold Star Families for Peace and Veterans Against the War.
Scott Gries / Getty