We also need such an inquiry. The consequences of that Iraq invasion have been horrendous. Almost 300,000 violent deaths resulted, more than two thirds of which were civilians. The resultant instability because of the absolute failure of an exit plan saw the rise of Islamic State with the ongoing horror and instability in the Middle East. The decision to invade was not based on sound evidence. If it was to be taken at all, it was premature and it was illegal. The UN weapons inspectors wanted more time. The best legal advice available said a further UN Security Council resolution was required to go to war. I released that legal advice on March 20. Prior to that, on February 26, 43 experts on international law and human rights published a letter saying that a war initiated by the “coalition of the willing” would be a violation of international law.

The weapons of mass destruction were not found. The claim that we would be a safer place as a consequence of the invasion is now risible. The ongoing instability and bloodshed in the region is a shocking reminder of a rash commitment. Loading Labor’s decision to oppose the war was not easy. It was a correct decision as history now shows us. It was a decision determined collectively, after much consultation, and had absolute regard to the available evidence. As leader of the opposition I had access to the available intelligence, which is appropriate and customary under our system. Without divulging the specifics I could not see the justification for our involvement, based on what was made available to me, and I told prime minister Howard that at the time. I made clear to the departing troops on the deck of the HMAS Kanimbla that while I opposed their deployment, I supported them. They had no choice, they had to accept the decision of the government of the day. Labor's opposition was to the government not to them.

I made it clear to US president George Bush on his visit to the Parliament that Labor remained a firm supporter of the ANZUS alliance but that the true test and strength of any alliance was the ability to tell good and trusted friends when they were wrong. That was such a time and history has confirmed it. We can’t reverse history but we must learn from it and be honest in our assessment of it. Hence my call for a much-needed full and open inquiry on what the extent of evidence at the time justified, how decisions were taken to commit us to war and their timing, and what are the lessons to be learnt. The most serious commitment a government can make is to send our troops to war. We need a post-mortem on how that decision was taken. Loading Replay Replay video Play video Play video

Today more than ever, in a period when there is much less trust in government and our political institutions, we need to reflect on how such a momentous decision should be made in the future. I am a great believer in the wisdom of counsel and in ensuring as best we can a level of bipartisanship for such a decision. It can’t be just a prime minister's call. We need to find a better way to ensure it is a process and decision of the Parliament. Simon Crean is a former Labor leader and cabinet minister.