Tony Blair has said that "many millions" of Muslims hold a viewpoint that is "fundamentally incompatible with the modern world."

Rejecting arguments that Isis is simply "tens of thousands of brainwashed crazies," he continued: "[Isis] does not seek dialogue but dominance. It cannot therefore be contained. It has to be defeated."

To mitigate against such attacks, the ex-PM argued for "active on-the-ground military support" for Arab armies, stating that Isis "have to be crushed."

He also called for the creation of a pan-national anti-terror force, saying: "We must build military capability able to confront and defeat the terrorists wherever they try to hold territory. This is a challenge for the West."

Inside Isis secret tunnels Show all 7 1 /7 Inside Isis secret tunnels Inside Isis secret tunnels Network of underground tunnels was discovered by Kurdish forces after they regained the town of Sinjar in Iraq Inside Isis secret tunnels A member of the Peshmerga forces inspects a tunnel used by Isis militants in the town of Sinjar, Iraq Reuters Inside Isis secret tunnels An entrance to the tunnel used by Islamic State militants is seen in the town of Sinjar, Iraq Inside Isis secret tunnels The secret tunnels allowed militants to freely move underground Inside Isis secret tunnels The tunnels appear to be wired with electricity Inside Isis secret tunnels Some of the tunnels are 30 feet deep Inside Isis secret tunnels Concerns remain that parts of the tunnels are rigged with explosives

His comments, made during a Sunday Times interview, come six months after he admitted that the existence of Isis could be blamed on Western intervention in the Arab world during the second Iraq war.

Asked by a CNN interviewer in October 2015 whether he thought the invasion of Iraq was a "principle cause" of the rise of Isis, he said:

"I think there are elements of truth in that... Of course you can't say that those of us who removed Saddam in 2003 bear no responsibility for the situation in 2015.

"But... it's not clear to me that even if our policy did not work, subsequent policies have worked better."

Former London student in Isis execution video

He warned that "increasingly frequent acts of terrorism" could culminate in an attack "of such size and horror" that it would result in "many more victims" than the recent attack on Brussels or 2015 attacks in Paris.

And he criticised those on the left who believe that "we have caused all of this through Western policy".

In 2014, a senior Isis commander told the Guardian that the Camp Bucca detention facility operated by the US-led coalition during the Iraq war was directly responsible for the rise of the theocratic state.