Nobody puts it better:
I am now forced to wonder: Who is there who does not know that the Bush administration decided after September 2001 to change the balance of power in the region and to enforce the Iraq Liberation Act, passed unanimously by the Senate in 1998, which made it overt American policy to change the government of Iraq? This was a fairly open conspiracy, and an open secret. Given that everyone from Hans Blix to Jacques Chirac believed that Saddam was hiding weapons from inspectors, it made legal sense to advance this case under the banner of international law and to treat Saddam “as if” (and how else?) his strategy of concealment and deception were prima facie proof. The British attorney general—who has no jurisdiction in these 50 states—was worried that “regime change” alone would not be a sufficient legal basis. One appreciates his concern. But the existence of the Saddam regime was itself a defiance of all known international laws, and we had before us the consequences of previous failures to act, in Bosnia and Rwanda, where action would have been another word for “regime change.”
Christopher Hitchens in Slate.