Bah, rules didn't apply to King George W. Bush. He was "the decider" and didn't think he needed congressional approval to invade Iraq at all....
The Presidents Constitutional Authority to Conduct Military Operations Without Congressional Approval
"CRAWFORD, Texas - President George W. Bush's lawyers believe he has authority to attack Iraq without asking Congress, the White House said on Monday, but
Democrats urged the president not act without seeking approval..."
White House lawyers: Bush doesn't need Congress to attack Iraq Israel News Broadcast | Haaretz
Bush started diverting funds, troops and resources authorized by congress for Afganistan and diverting them to Iraq in February 2002....almost nine months before he got a congressional resolution for Iraq in October of 2002. During that entire nine months he was heavily bombing Iraq.....
Annals of National Security: The Stovepipe : The New Yorker
Bush's Lost Year
"...Britain and the US waged a secret war against Iraq for months before the tanks rolled over the border in March 2003. Documentary evidence and ministerial answers in parliament reveal the existence of a clandestine bombing campaign designed largely to provoke Iraq into taking action that could be used to justify the start of the war.
In the absence of solid legal grounds for war, in other words, the allies tried to bomb Saddam Hussein into providing their casus belli. And when that didn't work they just stepped up the bombing rate, in effect starting the conflict without telling anyone...."
The war before the war