He's back. Tony Blair, invader of Iraq, "personal family friend" of the Gaddafis, holiday guest of Hosni Mubarak, godfather to Grace Murdoch, used the tenth anniversary of 9/11 not to apologise for British complicity in torture and rendition but to make the case for - yes, you guessed it - "regime change" in the Middle East.

“Ten years on, Blair says Iran is the real enemy", splashed the Times on its front cover. "If necessary, you've got to be prepared to use force to stop their military nuclear programme," the perma-tanned ex-premier told the BBC's Today programme, adding: "You cannot rule out the use of military force against Iran if they continue to develop nuclear weapons." Isn't it odd to have a Middle East "peace envoy" who constantly agitates for more war in the region? And isn't it even odder to witness Blair, once again, making unfounded assertions about the nuclear threat posed by a Middle East nation?

Iran isn't developing nuclear weapons. That's not just my view or Mahmoud Ahmadinejad's view: believe it or not, that's the view of the US intelligence community. The 2007 National Intelligence Estimate (NIE) declared with "high confidence" that Tehran had "halted" its nuclear weapons programme in 2003. The unpublished 2011 NIE report reaffirms this. Mohamed ElBaradei, former head of the UN's nuclear watchdog, the International Atomic Energy Agency, says he never saw any "credible evidence" that Iran was developing nuclear weapons and has described the threat as "exaggerated".

The big neocon

The former prime minister is not neutral. He has never hidden his belligerent agenda on the Middle East. "On foreign affairs, Tony is basically a neocon," says a former cabinet colleague and close ally of Blair. "Just as George Bush and the Washington neocons had planned to move on from Iraq to Iran, so had Tony."

Like the US neoconservatives, however, Blair has little knowledge or understanding of the religion, culture or history of the region. In January 2006, for instance, Channel 4's Jon Snow went to interview Blair in Sharm el-Sheikh in Egypt - where the latter had been on holiday with his family in one of Mubarak's villas - about the UK's response to the Asian tsunami. Once the interview was over, the conversation turned to Middle East politics.

“The problem with Iran," remarked Snow, “is that it all goes back to Mossadeq."Blair gave him a blank look. "You're going to have to remind me [who he is]," replied the then prime minister.

It was a remarkable admission. In 1953, as almost every Iranian knows, Britain helped depose the democratically elected prime minister of Iran, Muhammed Mossadeq, after he nationalised the country's oil industry, and reinstalled the despotic but pro-western shah.

Yet, despite his self-confessed ignorance of Middle Eastern history and his catastrophic misjudgement on Iraq, Blair retains a strange superiority complex. "Tony believes he has a unique ability to join up the dots and see the big picture," the Blairite ex-cabinet minister tells me. "The question is: do the dots exist and is he right to join them up in the way he does?"

Blair, for example, bizarrely conflates Shia-fundamentalist Iran with Sunni-fundamentalist groups including al-Qaeda and the Taliban. Like the US government, he claims that Iran supports and arms the Taliban in Afghanistan - a charge denied, incidentally, by the Afghan government. "Blair is obsessed with Iran but Iran isn't the problem in Afghanistan - it's Pakistan," Sherard Cowper-Coles, the UK's former envoy to Afghanistan and Pakistan, tells me. In public, the US and its allies accuse Iran of arming and backing the Taliban insurgency; in private, however, they take a different line. In a US diplomatic cable released late last year by - who else? - WikiLeaks, the then US defence secretary, Robert Gates, "noted that intelligence indicated there was little lethal material crossing the Afghanistan-Iran border".

Cowper-Coles agrees. "There is a relatively tiny covert operation by the Quds force of the [Iranian] Revolutionary Guard, sending small amounts of weaponry to some Taliban in the south of the country," he says. "But there is also evidence of the Iranians turning down requests from the Taliban for advanced weapons." The truth is that the Taliban's main supporters are based in Pakistan and Saudi Arabia, both western allies about whom Blair has said little.

No nuance

What Blair also omits to mention is that Iranian troops fought alongside the Northern Alliance against the Taliban in late 2001, while the Afghan president, Hamid Karzai, has admitted to receiving "bags of cash" from Tehran. Iran's interest, like ours, is in propping up the government. "The Iranians really don't want to stir things up in Afghanistan," says Cowper-Coles, author of the recent book Cables from Kabul. "As Shias, they do not want the Taliban to succeed. But nor do they want the Americans or Nato to have a great triumph."

Such nuance is beyond the messianic Blair. Iran is evil. The west is good. Military action works. "Blair simplifies and exaggerates," Richard Dalton, former British ambassador to Iran, tells me, "and thereby pushes a grossly distorted version of Iran's behaviour and helps to create a climate in which a pre-emptive attack on Iran would be regarded as justifiable." Such an attack would only strengthen anti-western hardliners in the Islamic Republic, which is why the leaders of the country's opposition movement are resolutely opposed to foreign military intervention.

Blair's delusions, hubris and wilful ignorance helped plunge Iraq into chaos and bloodshed. We cannot afford to allow him to do the same again with Iran.

Mehdi Hasan is senior editor (politics) of the New Statesman