Channel 4 news anchor Jon Snow said the Iraq War led to the rise of the so-called Islamic State and spawned the recent cascade of explosions.
As a journalist who worked in the country before the war, Snow said the military action blew apart a "very tender lattice work of Sunni and Shia relationships" that existed beneath Saddam Hussein's regime.
He believes the war "completely reopened the issue of the struggle" between the two faiths.
Speaking about the recent bombing in Baghdad, that claimed the lives of over 250 people, Snow said he thinks "it's Tony Blair's work."
The news anchor was speaking on Newstalk Breakfast ahead of the publication of the Chilcot Report - the inquiry set up to examine the UK's role in the invasion of Iraq in 2003.
The document will be released at 11am this morning and runs to 2.6 million words, which is five times longer than War and Peace.
Tony Blair is one of those expected to be criticised in the report, as he was British Prime Minister at the time.
When asked if Blair would be feeling nervous this morning, Snow said that he's "arrogant enough" not to be.
"He’s been strutting around making judgements and speeches about other international issues of late.
“He seems to have lost none of the shine, none of his arrogance and I’m sure he’ll continue along that path."
Jon Snow added: “The word is that the Foreign Secretary at the time, Jack Straw, is in a fair amount of trouble.”
He said the most damning area of the report is likely to be the attempts made to "fix and massage the law" allowing the UK to undertake the war - a conflict that former United Nations General Secretary Kofi Annan had declared illegal.
In Britain the Foreign Office has its own legal department, which seeks to ensure that the Government of the day behaves legally.
"The lower echelons of the legal department continuously sent up the line judgement that this war was illegal and would require a specific UN resolution," said Snow. However that resolution was never 'winnable'.
"This was a war seeking regime change in Iraq and that is something that the United Nations would never sanction.
"A force going in to remove the leader of another country has never been in the legal ambit of the UN’s capacities."
Jon Snow also believes that this will be the final inquiry into the Iraq War, after four previous ones.
“I suspect Chilcot has done quite a thorough job,” he said. “I don’t see anybody else trying to dig any further.”
The report will be released later this morning and culminates more than seven years of work.