Hussein didn't just wake up one day and thought, what am I going to do today?
hmmm...
let's annex Kuweit!
There were growing tensions, between both contries before.
Saddam saw Iraq as a shield of the arabic world against the spreading of the Iranian revolution.
That is why he asked for financial help especially in Kuweit after the war against Iran. I think he wanted 1 billion US$.
There was a comment made by the US ambassador shortly before the invasion, that the US would stay out of the conflict. That's why Saddam thought he could get away with it.
So we would need a stroger involvement of the US in the conflict to prevent the invasion.
A bancrupt Iraq is not that likely to imagine.
Nobody b ut Iran would profit from a collapse of Iraq. So it would be prevented somehow.
Saddam Hussein didn't belong to political Islam before 1990, he even had a Christian foreign minister before the Invasion.