Iraq, WMD and The Dodgy Dossier

I know that this is all old news, but the topic is raised regularly on programmes like Question Time*, so I'd just like to see how far we get by applying logic. From the foreword to The Dodgy Dossier, signed off by the then Prime Minster Tony Bliar himself:

... the document discloses that his military planning allows for some of the WMD to be ready within 45 minutes of an order to use them. I am quite clear [sic] that Saddam will go to extreme lengths, indeed has already done so, to hide these weapons and avoid giving them up... I believe that faced with the information available to me, the UK Government has been right to support the demands that this issue be confronted and dealt with. We must ensure that he does not get to use the weapons he has, or get hold of the weapons he wants.

My issue is that there is an inherent contradiction here:

1. Let's assume it were true that Saddam could have wiped us all out within 45 minutes; in that case, invading Iraq would be a suicidal project unless the whole country could be overrun within say half an hour and without warning. During The Cold War it was widely accepted that each side had the technical capability to annihilate the other side within half an hour or so. Which is why NATO and The Warsaw Pact fought no end of proxy wars (Africa, Central America, Afghanistan and before then in Korea and Vietnam) but the chance of either side attacking the other directly was negligible.

2. Alternatively, we know that Bush & his poodle Bliar were itching to depose Saddam. We will never really know whether that was because Saddam tried to assassinate George H W Bush, allegedly; whether it was to try and secure access to Iraq's oil (unlikely, even though David Frost once tricked Donald Rumsfeld into admitting that it was); general macho bravado; or simply because it was to the advantage of the US 'military industrial complex' (as Dwight Eisenhower, a Republican, warned in his farewell address as US President back in early 1961; "The potential for the disastrous rise of misplaced power exists and will persist."). But surely they would not have contemplated an invasion - having announced it months in advance -  if it were really true that Saddam could have retaliated by rendering vast swathes of the Middle East and eastern Mediterranean countries uninhabitable?

* e.g. last Thursday, where Jack Straw refused to concede that he would have voted against invasion had he known then what he knows now. It was nice to see Lib Dem spokesman Brian Eno and UKIP Leader Nigel Farage at one on this issue.