But in the eight years since the U.K. joined the U.S.-led invasion, Blair has perfected the art of outfoxing angry Brits. The ex-prime minister was already safely inside the building by the time protesters began chanting "Blair lied, thousands died," and "Justice prevail, Blair in jail." He had arrived two hours earlier in a chauffeur-driven car, traveling, the anti-Blair Daily Mail noted, "under cover of darkness."
Despite the disapproval of his nation, Blair has never faltered in his belief that it was right to attack Iraq. At his first appearance before the inquiry in January 2010, he was grilled for six hours about the buildup to war and the chaos that followed Saddam Hussein's overthrow. Blair offered a consistent defense of his actions, stating that the terrorist attacks of Sept. 11, 2001, had turned Saddam into a greater, more pressing threat for the Western world, and that he would do the same all over again.
Today, he appeared even more convinced of the merits of military intervention. Dressed in a finely tailored blue suit and boasting a deep orange tan, Blair said that the strikes on the World Trade Center and the Pentagon on 9/11 had ushered in a new, deadlier form of terrorism.
"The single most difficult thing we have to face today ... is the risk of this new type of terrorism and extremism based on an ideological perversion of the faith of Islam combined with technology that allows them to kill people on a large scale," he said. "This is a time where many people think this extremism can be managed. I personally don't think that is true. I think it has to be confronted and changed."
That's an echo of the argument Blair repeatedly made in the buildup to war: that unless the world deposed Saddam, terrorists would eventually get hold of his weapons of mass destruction. (Those weapons were never found.)
"To my mind, Iraq, Saddam Hussein, had nothing to do with 9/11, and I have never seen anything to make me change my mind," Eliza Manningham-Buller, the former head of domestic intelligence service MI5, told the five-member panel in July.
The inquiry went on to probe the central accusation made by many British opponents of the war: that Blair told Bush Britain would join the invasion as early as April 2002, a year before parliamentarians approved U.K. involvement in the invasion. Before today's session, British officials had refused to publish a set of letters sent between the two leaders in 2002. Blair supported that decision, saying it was important that statesmen had the option to "communicate in confidence."
The ex-prime minister denied ever offering Bush his unconditional support. Instead, he revealed that he told the president, "You can count on us, we are going to be with you in tackling this, but here are the difficulties." The message he wanted to communicate, Blair explained, was: "Whatever the political heat, if I think this is the right thing to do I am going to be with you, I am not going to back out if the going gets tough. On the other hand, here are the difficulties and the U.N. route is the right way to go."
Although the inquiry is focused on past events in Iraq, Blair used the session to again warn about the growing threat posed by Iran -- a subject he raised repeatedly during last year's appearance. "I see the impact and influence of Iran everywhere [across the Middle East]," said Blair, who now serves as a peace negotiator between Israel and the Palestinians. "It is negative and destabilizing."
In an apparent rebuke of President Barack Obama's attempts to reach out to the Islamic Republic, Blair said it was time for the West to end its "wretched posture of apology" toward Tehran. He cautioned that the West must be prepared to use force, as the Iranian regime would continue to pursue the development of nuclear weapons unless they were met with the "requisite determination."
"I wanted to make [it] clear that, of course, I regret deeply and profoundly the loss of life," he said, "whether from our own armed forces, those of other nations, the civilians who helped people in Iraq or the Iraqis themselves."
Some members of the audience weren't convinced by this belated show of sorrow.
"It's too late!" shouted Rose Gentle, whose 19-year-old son, Fusilier Gordon Gentle, died in the southern Iraqi city of Basra in 2004.
"Your lies killed my son," she added, before walking out of the room. "I hope you can live with it."