On 11 March 2003, Wilkie resigned from the ONA, stating that while it was likely that Iraq did possess weapons of mass destruction, its program in this area was contained, that international sanctions were having an effect, and therefore an invasion was premature and also reckless in potentially provoking Saddam Hussein to use those weapons and possibly even begin supporting terrorism. He told the ABC: "I think that invading Iraq at this time would be wrong. For a start, Iraq does not pose a security threat to any other country at this point in time. Its military is very weak, it's a fraction of the size of the military at the time of the invasion of Kuwait. Its weapons of mass destruction program is very disjointed and contained by the regime that's been in place since the last Gulf War. And there is no hard intelligence linking the Iraqi regime to al-Qaeda in any substantial or worrisome way." Wilkie later told the press that in the lead up to his resignation he had increasingly encountered ethical conflict between his duty as an intelligence officer and his "respect for the truth". In 2016, after appearing at the Chilcot enquiry, Wilkie said the notion that Iraq had weapons of mass destruction and co-operated with terrorists had been "a lie ... No wonder John Howard and Tony Blair and George W Bush do stand accused of war crimes”. He linked the 2005 Bali bombings and the 2014 Lindt Cafe siege to Australia’s participation in the invasion of Iraq.