Einstein once defined insanity as doing the same thing over and over again and waiting for different results, so perhaps it was madness to hope Tony Blair, appearing for the second time at the Iraq Inquiry, to tell us anything new. But whilst there were no big revelations over the decisions he made in the build-up to the invasion of Iraq, the former prime minister’s statement before a number of grieving parents who had lost family members in the war, that he ‘deeply and profoundly regrets the loss of life’ caused something of a stir.

As he came to the end of a bravura four-and-a-half hour performance during which he robustly defended all his decisions over Iraq and even used the platform to urge possible military action against Iran, Blair decided to take the opportunity to express sorrow for deaths resulting from the war. But his statement was met by jeers of derision from the military families attending the hearing. ‘Too late!’ cried one woman. Two others stood up and left the room. Rose Gentle, whose son Gordon was killed in Basra in 2004, looked Blair in the eye and told him, ‘Your lies killed my son.’

Looking sun-tanned and relaxed, the ex-PM had strode into the hearing room that morning, taking his seat before the five-person panel led by an avuncular Lord Chilcot. The inquiry, officially launched in July 2009, is intended to identify lessons that can be learned from the Iraq conflict and has so far heard testimony from scores of key government and military officials from the time. Tony Blair, who testified last January, was recalled in order to clarify some discrepancies between his earlier evidence and that of later witnesses. Indeed, before today’s hearing there was speculation that the inquiry might demonstrate that he had deliberately misled his cabinet, parliament and the British people.

During questioning Blair dismissed suggestions that he had committed British troops for the US-led invasion long before the issue was discussed in cabinet or debated in parliament. Earlier this month Lord Goldsmith, the government’s chief law officer at the time, had told the inquiry that in October 2002 he learned that ‘the prime minister had indicated to President Bush that he would join the US in acting without a second security council decision if Iraq failed to take the action that was required by the draft resolution [1441].’ Blair explained this away by saying that he had not wanted to ‘start raising legal issues’ with President Bush until he was absolutely sure of the British legal position.

Indeed, he did not deny that in January 2003 he had assured George Bush that he was ‘solidly’ with him despite the fact that it was not until two months later, on the eve of the invasion, that Lord Goldsmith had given Blair the formal legal advice that a ‘reasonable case’ could be made for launching an attack without further UN backing.

Challenged as to why, in direct contradiction to advice provided by Lord Goldsmith, Blair had told Parliament on 15 January that in certain circumstances a second UN resolution would not be necessary, Blair said that he had been ‘making a political point’ rather than ‘a legal one’.

Anyone hoping for this to be a judgment day for Blair was in for a sore disappointment. Instead, ‘Teflon Tony’ rose to the occasion, defiantly repeating his ‘I did what I thought was right’ mantra and once again using the platform to warn of the ‘destabilizing’ and ‘negative’ influence of Iran. At his first appearance before Lord Chilcot, Blair managed to mention Iran no less than 58 times. Today, although his first reference to Iran came within the first three minutes of his testimony, it was only at the end of his session that he went into detail about the ‘looming, coming challenge’ posed by Iran.

When asked what lessons he took from the Iraq war, Blair replied: ‘The link between AQ [al-Qaeda] and Iran.’ He went on to say that ‘we must get our heads out the sand’ and meet the Iranian threat with ‘the requisite determination and, if necessary, force’. The Middle East peace envoy has clearly lost none of his thirst for war.

Outside the hearing, as the former prime minister prepared to leave, the chants of demonstrators could be clearly heard:  ‘Mr Blair, to the Hague.’ Whilst Blair will never have to face the International Criminal Court, his religious beliefs meant that in own mind he will one day face a higher form of judgment. ‘In Catholic terms there are three clear steps for forgiveness: confession, firm purpose of amendment and penance,’ veteran peace campaigner and former Roman Catholic priest Bruce Kent tells me outside the Inquiry. ‘Mr Blair has done none of these.’

Though Tony Blair has made it clear that he feels no guilt, he clearly does feel a sense of responsibility: responsibility for the decisions made in office and responsibility for the blood price paid by British soldiers as well as Iraqis. By repeating the mantra ‘I did what I thought was right’, he may be able to insulate himself from some of the guilt, but as news this week comes in of 130 deaths in Iraq, that decision must still weigh heavily on his sun-kissed shoulders.

In those heady days in 1997 a newly elected Blair said in a speech: ‘Mine is the first generation able to contemplate the possibility that we may live our entire lives without going to war or sending our children to war.’ Two wars and countless deaths later, he must sometimes ask himself where it all went so horribly, horribly wrong.