The decision to go to Iraq war was one of the most controversial episodes of Blair.

Former British Prime Minister Tony Blair is appearing Friday before an inquiry into the Iraq war to face further interrogation over his decision to join the US-led invasion in 2003.

Blair, who sent 45,000 British occupation troops to join the U.S.-led invasion in 2003, told the inquiry in his first appearance that Saddam Hussein was a threat to the world who had to be removed or disarmed.

Blair acknowledged that intelligence about Iraq's stockpile of weapons was false. But he said he led the country into war because he couldn't take the risk of Iraq reconstituting its weapons programme.
The US and UK had gone to war, saying Iraq possessed "weapons of mass destruction" - an accusation that later proved to be unfounded.

He also said he had no regrets about the military action, a comment that angered some of the relatives of the 179 British soldiers killed in Iraq.

The inquiry, which began in November 2009 and is headed by former civil servant John Chilcot, was set up by Blair's successor Gordon Brown to learn lessons from the conflict and is not designed to assign guilt or blame to any individual.

The decision to go to war was one of the most controversial episodes of the ex-prime minister's 10-year premiership, which ended in 2007. It led to massive protests and accusations he had deliberately misled the public over the reasons for the invasion.