Tony Blair has sparred with John Humphrys over his prime ministerial record.
The BBC Today interviewer asked Blair whether he believed the "war on terror" had been won. "We've achieved significant results . . . but I don't think this is over," he replied. I think the radical Islamism which gave rise to this terrorist group is still with us, still powerful."
In a wide-ranging 28-minute interview, taking in Iran, extraordinary rendition and the death toll in Iraq, Blair repeated several times his belief that al-Qaeda was part of a "bigger, broader picture". He also said he had no knowledge of British collusion in the torture of detainees who had been subject to extraordinary rendition: "You can't know everything the security services are doing."
Here are some of the key exchanges.
On the "war on terror":
Tony Blair: The real question is not whether you call it the war on terror or you don't, it is: what is the nature of the threat? I think the most interesting and difficult question for me ten years on is: was this a group of isolated people, terrorists, with an ideology, who committed a terrible atrocity or was this group at the furthest end of a spectrum of what I would call radical Islamism, and therefore this is something far bigger, far greater than even we assessed after September 11 . . .
I don't think you can treat these people as just a weird and warped group with no connection to the wider world.
On the threat of Islamism:
TB: When I'm in the Middle East, and you see the activities of the Muslim Brotherhood, or Hamas, you look at the role that Iran is playing in the region, I think it's a big mistake to say this was just about Bin Laden and a group of terrorists. That's my view.
John Humphrys: The fact you pitched the "war on terror" at every stage against the worst that we could imagine led to appalling consequences.
Tony Blair: I wouldn't agree with that. I think the difficulties we had in Afghanistan or Iraq - we removed the regimes actually quite easily, the Taliban in a couple of months and Saddam in two months - what then happened is the very forces I'm talking about combined together, Iran from the outside, al-Qaeda from the outside, insurgents from inside, in order to try to destabilise those countries.
On the death toll in Iraq:
JH: That's rather the dismissing the consequences of what you did . . . Look at Iraq. The deaths of tens - most people believe hundreds - of thousands of entirely innocent people. . . Many more than had been killed in any acts of terrorism.
TB: The figure that the Iraq Body Count gives is over 100,000.
JH: Johns Hopkins [university]... 650,000.
TB: Those figures were hugely discredited.
TB: Let's look at what we did in Afghanistan and Iraq. What we did was remove a brutal and repressive dictatorship.
JH: ... that wasn't threatening us. Or the Western world.
TB: I disagree. I think the Taliban harbouring al-Qaeda was threatening us. I think Saddam was undoubtedly a threat.
JH: How? He didn't have weapons of mass destruction, as we now know.
TB: He was in breach of United Nations resolutions going back many years, and had used chemical weapons against his own people. And by the way, started two wars in the region.
On how Blair dealt with Bin Laden:
JH: You went off on the wrong foot and created massive problems.
TB: That is to assume that the problem was Bin Laden and a group of terrorists. That comes back to the difference in analysis between us - if you were right, then now that Bin Laden is dead, you would expect to find this radical Islamism dying with him. But it's not. Look at Nigeria, Somalia, look at what's happened in the Middle East, in Lebanon, look what's happening in Yemen today. Look at what's happening in all of these countries where radical Islamism is developing. It's not about one man.
JH: And we're not dealing with all of those by invading those particular countries.
TB: Iran was a threat before Saddam.
JH: But it's a greater threat now.
TB: It's a threat that has been growing for a period of time. The reason it's a bigger threat now is not because Saddam has gone in Iraq.
JH: Oh, it is. [Ahmedinajad] has influence in Iraq that he didn't have before.
TB: That is correct that Iran is trying to influence Iraq in a way that is deeply unhelpful. My answer to that is you deal with Iran.
JH: What do you do to Iran?
TB: If necessary, you've got to be prepared to use force to stop their military nuclear programme.
JH: What kind of force . . . could it include invasion?
TB: No, I don't think it would include invasion, but I think you cannot rule out using military force against Iran if they continue to develop nuclear weapons.
You can listen to the full interview here. It begins around the 1.32 mark.