I think one point overlooked is that there were many people who believed that the anti-Saddam faction in Iraq was powerful enough to fill the void after the fall of the Ba'ath Party's leader.
I clearly recall the glee with which I think most people - certainly here in the West - greeted the live televised pictures of Saddam's statue being demolished by Iraqi citizens.
It is not unreasonable, in my view, to suspect that there were many politicians in the West that also thought the anti-Saddam forces would gather swiftly and bring stability in the aftermath. It's all very well and good to say that it was an ill-conceived adventure, but the subsequent interference of Iran and Al-Quaeda took many by surprise.
As I said, hindsight is a very valuable commodity.
I don't necessarily agree Nick, having regard to the recent conflict between the two nations, the possibility of an Iranian move in the aftermath of regime change within Iraq would certainly have been taken into account - to have disregarded that possibility would have been reckless.
An assessment would also have been made of the likelihood of the new regime having the expertise and organisation to assume to role of government in the light of so many years of oppression under Saddam. In planning, the factional nature of the various groups - and their newly found freedom - would also have been assessed, again, failure to have done so would have been asking for trouble.
Hindsight should have been employed before this operation was engaged, as it would undoubtedly have shown that this region has a habit of bringing grief to those who interfere by way of military force. This is why I regarded this war – and still do – as an ill-conceived operation in the face of all that was known or should have known about the actors in the region.
I doesn’t appear to me that such doe-eyed confidence was employed by the United States in the expectation of a smooth transition of power - the hope was certainly there - but the possibility of the operation going tits-up as a result of some of the factors I have mentioned would certainly have been taken into account.
On foot of all that, I still maintain that this war was wrong-headed in its implementation and there was no need for our country to become involved with the United States in the way we did.
I wouldn't vehemently disagree with what you say, Zulu. Of course, the aftermath would have been considered, but I believe that there may have been excessive optimism with regard to the anti-Ba'ath Party factions. Unfortunately, when you have years of dictatorship, opposition is often unable to be co-ordinated and so, when the suppression is removed, there is no cohesive force. Of course, as you rightly point out, the Middle East is full of tribal factions - often supported by outside states, so there was always a good chance that it was going to go tits-up as you say. Since I believe the casus belli was regime change, maybe that single goal blinded the decision makers enough to make them underestimate the potential downsides.
Either way, it was probably foolish to go to war (though one must necessarily wonder how history would have turned out if Saddam had remained in power), and it was foolish not to have given more weight to the aftermath - if, indeed, any real attention was paid to that. If that is the case, then I seriously think that the US administration was naive to the point of sheer recklessness.
close to the point.. but not complete..
there are many intelligent think tank institutes in US of which primary goal is mainly politics,strategy and economy and very clever minds there in everyday spending whole their energy and ideas and theories on that subjects..
now 2 choices exist
1. either US administration dont spend even one second to ask them what can happen after

(which is most likely what happened)
2. the think tank(s) mislead the administration which is in my opinion is utter 'dangle berries' and impossible..
now dont they (US administration) know they can get detailed probability plans from those organizations , yes they know but problem is something pushed them even not to ask!!!
that something was rather cartels, and their working partners in administration..
they have to have that war whatever price would be there to be paid by public ,
forget about Saddam , he was a created puppet finished his time, rebel against the master and destroyed by the master..