Few men have spent more time at the intersection of nuclear weapons and international politics than Swedish diplomat Hans Blix.

As the former head of the International Atomic Energy Agency (IAEA) and then chief United Nations weapons inspector, Blix was at the centre of events when he publicly contradicted claims from the administration of former US president George W Bush that Iraq had weapons of mass destruction (WMD). It was an assessment the US pushed aside.

Blix also accused the British government of dramatising the threat of weapons in Iraq in order to strengthen its case for joining the 2003 war against Saddam Hussein. No stockpiles of weapons of mass destruction were ever found.

In his 2004 book Disarming Iraq, Blix gives an account of the events and inspections before the coalition began its invasion.

"I am sorry for the way it went because we failed, and if we had persuaded the UN Security Council and persuaded the world, then there might not have been a war," he said.

Recent talk about a possible attack on Iran’s nuclear installations has made Blix concerned about a repeat of the events that led to the Iraq war.

"When I hear [Israeli Prime Minister] Netanyahu saying it’s not a question of days or weeks, but also not years, I think that sounds like a terrible threat," he says.

In this interview with Al Jazeera, Blix discusses Iran's nuclear programme and how to stop what he calls a "legally unjustified" attack against Tehran. Is Iran trying to develop a nuclear weapon? Is an Israeli attack on Iran coming?

Talk to Al Jazeera airs each week at the following times GMT: Saturday: 0430; Sunday: 0830, 1930; Monday 1430. Click here for more on Talk to Al Jazeera Click here to follow Talk to Al Jazeera on Facebook