David Miliband has said his support for the invasion of Iraq is “one of the deepest regrets” from his time in politics. The former foreign secretary also said the 2003 war and the period around it have caused “real damage” to western claims to stand up for core values of international order and justice. “I voted for the war. I supported the government’s position,” he told an audience at the Hay festival in Wales. “There’s no question in my mind about quite how serious a mistake that was.” Miliband – who was in conversation with David Runciman and Helen Thompson for an event presented in partnership with the London Review of Books – went on to describe the war as “a strategic mistake”, partly because of “the global lesson that it allowed to be taught”. “I don’t believe, myself, that it excuses what’s happened subsequently in Ukraine,” he said, but agreed that some may see the west as being hypocritical in its anti-Russia stance. “I think it’s a very, very serious point.” Miliband said he worried a lot about the way he saw the world as being divided. “Ukraine has united the west, but it’s divided the west and wider parts of the world,” he said. Countries representing more than 50% of the global population have refused to back the condemnation of Russia, despite the fact they understand that “a grotesque abuse of international law” has taken place. While just five countries have supported Russia at the UN, “40 or 50 countries have refused to join any condemnation, not because they support the invasion of Ukraine, but they feel that the west has been guilty of hypocrisy and weakness in dealing with global problems over the last 30 years”, Miliband said. The chief executive of the International Rescue Committee encouraged the audience to read the speeches of Kenya’s president, William Ruto, who “talks about how the effort in Ukraine should be contrasted with the effort to tackle those other wars in other parts of the world”. Miliband said Ruto and others like him have made the point that “yes, Ukraine has enormous poverty and crimes against its own population, but what about Ethiopia, what about Afghanistan, what about Palestine? “And I think that’s what we have to take very, very seriously if we want to understand what’s the role of the west, never mind the UK, in global politics.”