This post isn’t designed to convince those who think the Iraq War was Bad, that it was Actually Good. It is a sincere attempt to imagine a world where Saddam Hussein was still in power. I acknowledge that the counterfactuals laid out below were used in the framing in the lead up to the war - but, in any event, any justification found below for the Second Gulf War says nothing about the execution of the war, or US/UK policy in Iraq following the fall of Saddam’s regime.
As I’ve explained at length elsewhere, those who decry that it perfectly knowable that Saddam didn’t have a sizeable stock of WMDs ignore that Saddam’s policy was explicitly to have strategic ambiguity about WMDs. Saddam’s rationale for this has now long been known: he was more threatened by Tehran and Tel Aviv, than he was Washington or London:
Saddam was asked about the weapons during a meeting with members of the Revolutionary Command Council. He replied that Iraq did not have WMD but flatly rejected a suggestion that the regime remove all doubts to the contrary, going on to explain that such a declaration might encourage the Israelis to attack (Explaining the Iraq War, Harvey (2011), p.251)