Media playback is unsupported on your device Media caption Tony Blair: "Don't believe washing our hands of it and walking away will solve the problem"

The 2003 invasion of Iraq is not to blame for the violent insurgency now gripping the country, former UK prime minister Tony Blair has said.

He told the BBC there would still be a "major problem" in Iraq even without the toppling of Saddam Hussein in 2003.

He insisted the current crisis was an issue that "affects us all" and urged more western intervention in the area.

Critics have rejected the comments as "bizarre" with one accusing Mr Blair of "washing his hands of responsibility".

Image copyright AP Image caption Shias in Iraq have been urged to take up arms against the Sunni militants

Mr Blair said the idea that Iraq today would be stable if Saddam had been left in place was "simply not credible".

"Even if you'd left Saddam in place in 2003, then when 2011 happened - and you had the Arab revolutions going through Tunisia and Libya and Yemen and Bahrain and Egypt and Syria - you would have still had a major problem in Iraq," he said.

"Indeed, you can see what happens when you leave the dictator in place, as has happened with Assad now. The problems don't go away."

Where the extremists are fighting, they have to be countered hard, with force Tony Blair

He also called for some form of intervention in neighbouring Syria, warning that inaction would result in a threat to UK soil.

Mr Blair was prime minister when UK and US forces controversially invaded Iraq in 2003 - on the basis that it had weapons of mass destruction - with the last of Britain's troops withdrawing in 2011.

Now, uprisings by the al-Qaeda breakaway group the Islamic State in Iraq and the Levant (ISIS) have led to a surge of violence and sectarian killings in recent days.

The Sunni insurgents have advanced north of Baghdad.

And as Iraqi government forces attempt to hold them back, a US aircraft carrier has been deployed to the Gulf in response to the escalating violence.

'Unending violence'

Mr Blair said the idea that Iraq would be stable if the UK and US had not intervened "just isn't true" and that the current crisis involved the wider region as a whole.

In an essay on his website, he said the violence in Iraq was the "predictable and malign effect" of inaction in Syria.

But Michael Stephens, from the Royal United Services Institute, insisted the Iraq War had a part to play in the recent upsurge in violence.

"I think Mr Blair is washing his hands of responsibility," he said. "But at the same time, I do agree with him that we can't just ignore this.

"We do have some kind of role to play in terms of trying to make sure that both Iraq and Syria do not fragment and just move on into sort of unending violence."

Sir Christopher Meyer, Britain's ambassador to the US from 1997 to 2003, said the handling of the campaign against Saddam Hussein was "perhaps the most significant reason" for the current sectarian violence.

"We are reaping what we sowed in 2003. This is not hindsight. We knew in the run-up to war that the overthrow of Saddam Hussein would seriously destabilise Iraq after 24 years of his iron rule," he said in the Mail on Sunday.

Syria is three years into a civil war in which tens of thousands of people have died and millions more have been displaced.

In August last year, a chemical attack near the capital Damascus killed hundreds of people.

In the same month, UK MPs rejected the idea of air strikes against Syrian President Bashar al-Assad's government to deter the use of chemical weapons.

Image copyright Reuters Image caption Thousands of Shias are reported to have volunteered to help halt the advance of ISIS

"You do not need to engage as we did in Iraq or Afghanistan, but you need to recognise that we have interests in this," Mr Blair told the BBC.

'Bizarre views'

Clare Short, a former Labour minister who resigned over the Iraq War, said Mr Blair was "absolutely, consistently wrong, wrong, wrong".

"He has become a complete American neo-con, who thinks military action, bombing, attacking will solve the problems and it's actually making more and more tension, anger, division and bitterness in the Middle East," she told Sky News.

Image copyright AP Image caption Shias in Iraq have been urged to take up arms against the Sunni militants

Security analyst Professor Eric Grove said he found Mr Blair's position to be "bizarre".

What will [be] the impact on the streets of London and Bradford and others? Iraqi ambassador in Washington Lukman Faily on the prospect of international inaction

"So saying this is a result of our non-intervention, if Mr Blair really thinks that going into Syria and basically fighting everyone was going to lead to a better situation, I think his views are somewhat bizarre actually. I can see very little logic in this."

But former Middle East minister Alistair Burt said there was a "great danger" of trying to understand the situation by going back to "one root cause" and "blaming what was done in the past".

The Iraqi ambassador in Washington, Lukman Faily, meanwhile, said that, without international help, the effects of the crisis would be felt in the UK.

"What will [be] the impact on the streets of London and Bradford and others?" he said in an interview for BBC Radio 4's The World This Weekend.

He added: "These jihadists are coming from all over the world, so do you want these jihadists to go back to their country, in Bradford and elsewhere, to learn [sic] what they have practised in Iraq?"

The Iraq War has been the subject of several inquiries, including the Chilcot inquiry - which began in 2009 and whose report has not yet been published - into the UK's participation in military action against Saddam Hussein and its aftermath.