Tony Blair has said critics who believe the violence in Iraq today is a result of the 2003 invasion are "profoundly mistaken".
Speaking to Sky News' Dermot Murnaghan, he said the West's inability to get tough with Syria's Bashar al Assad and failure in Libya had allowed terrorism and chaos to spread across the Middle East.
And he said had he still been an MP he would have voted for military action against Mr Assad in Syria last year, when Labour leader Ed Miliband made the case against intervention.
The former Prime Minister said if the UK had not acted to get rid of Saddam Hussein 11 years ago the country would have been in a worst state than Syria now.
He said Britain had to "get involved" to end the crisis in the Middle East but he was not suggesting a "full-scale intervention" with troops on the ground like in 2003.

Mr Blair, who is now Middle East peace envoy, argued there was no way Britain could stay out of Syria because "ultimately, extremist groups also intend to target us".
He said security services in the UK, Germany and France now all say the greatest risk to those countries is jihadist fighters returning from Syria.
He said: "Some people will say 'well if we hadn't removed Saddam in 2003 we wouldn't have the problem today in Iraq and the reason I think that is profoundly mistaken is this: since 2011 there have been these Arab revolutions sweeping across the whole of the region - Tunisa, Libya, Yemen, Egypt, Bahrain, nextdoor to Iraq in Syria - and we can see what would have happened if we left Saddam there in 2003.
"We have left Bashar Assad in Syria. The result is that there have now in the last three years in Syria been virtually the same number of people killed in Syria as in the whole of Iraq. You have had nine million people displaced from Syria, you have chaos and instability being pushed across the region."
'Inaction over Syria' is to blame, says Mr Blair He suggested the West may have to accept that Mr Assad would have to stay but that an agreement would have to be reached and a new constitution and "inclusive government" formed.
He also cautioned working with Iran after the president Hassan Rouhani offered to co-operate with the US to tackle the Iraq insurgency.
Former Deputy Prime Minister Lord Prescott said he disagreed with Mr Blair and accused him of wanting to wage some kind of Medieval crusade in the Middle East.
He said in 2003 Mr Blair had insisted the invasion was not about regime change but pointed out that in his interview on Sky News, Mr Blair admitted it had been.
He also cautioned against the use of drones as an alternative way of intervening because the public would not accept the case for troops on the ground.
Iran's president Rouhani has said he would consider working with the US Former Labour International Development Secretary Clare Short said Mr Blair was "wrong, wrong, wrong" on the issue and accused him of being a "complete American neocon".
She said further intervention was not the answer telling the Murnaghan programme: "Who are you going to bomb? Remember Northern Ireland. When there is an uprising backed by some of the people, if you bomb you kill some of the people and make the people more angry and strengthen the forces of opposition."
In Iraq, the defence ministry said its forces are having some air strike successes against fighters from the Islamic State in Iraq and Syria (ISIS) who have made dramatic gains in the Sunni heartlands north of Baghdad after overrunning Iraq's second-largest city, Mosul.
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