My tuppence ha'penny (2 cents in US money):
Its not all about oil - although as the article said, it would be foolish to assume that oil is not a huge factor behind the reasoning of the US and UK.
It's a highly unpredictable situation. It could go one of several ways.
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The most optimistic outcome is that after a sudden and totally enveloping aerial attack that breaks up the Iraqi C&c structure coupled with a competent psych ops campaign, allied troops move over the border to witness mass desertions by disaffected conscripts. The only resistance is form the republican guard who are quickly outnumbered.
The conflict is over within months, and a caretaker government is installed with free and fair elections to follow.
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On the other hand, the disaster scenario is also a possibility. Saddam knows that if the allies invade with the explicit objective of 'regime change' he will either die or be captured.
Staring this fait accompli in the face as the allied invasion begins, his fury dictates his actions and he does his level best to turn the entire middle east into a giant bloodbath.
The invasion drags on for months as the iraqi scorched earth policy leaves huge population centres contaminated, public support sags as poison gas victims die on the television.
Israel, suffers a direct hit from an iraqi warhead and replies immediately with a tactical nuclear strike. Syria and Egypt kick off at Israel, US UK kicks off at Syria and europe runs for cover.
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And every outcome inbetween (and some more extreme ones too)
That's the chief difficulty with initiating armed conflict: the politicians have to light the blue touch paper and retire. After that their input is er, less valuable. They may direct their forces (usually against the advice of the military), but the course of the conflict is competely out of their hands.
If I lived in the US, I'd be a whole lot more sanguine about the war, but living in europe, in a lovely suburb that is about 50% muslim, I have my fears for the can of worms being opened by the Blair Bush axis of 'good'.