A newly leaked memo said the only way the allies could justify military action was to place Saddam Hussein in a position where he ignored or rejected a United Nations ultimatum ordering him to co-operate with the weapons inspectors. But it warned this would be difficult. "It is just possible that an ultimatum could be cast in terms which Saddam would reject," the document says. But if he accepted it and did not attack the allies, they would be "most unlikely" to obtain the legal justification they needed. The suggestions that the allies use the UN to justify war contradicts claims by Blair and Bush, repeated during their Washington summit last week, that they turned to the UN in order to avoid having to go to war. The attack on Iraq finally began in March 2003.