Suppose that after the first Gulf War Mr. Hussein realized that he could not defeat the US via nuclear, biological or chemical weapons. So, he created the false impression that he was pushing in this direction while he spent his petrodollars funding terrorist organizations. It is well known that he paid a bounty to the family of Palestinian suicide bombers. Why should we believe he stopped there?
Moreover, after the first Gulf War Mr. Hussein had to sell Iraq's oil through the UN Oil For Food program. This was a corrupt scheme that used petrodollars to buy pretty much everything except food. Given the fact that a lot of cash has ended up in the hands of Islamist insurgents working in post-war Iraq, I think it quite likely that this money went to terrorists. It may be that there was a lot more Iraqi than Saudi money bankrolling Mr. Bin Laden. If so, it may be that shutting off the flow of Iraqi petrodollars afforded the US the most leverage in the Global War on Terror (GWOT).
The Iraq war has alienated the US from the French and the Germans as well as the UN. However, it may be that their opposition was motivated by corrupt dealings in the UN Oil For Food program.
All of this is hypothetical. The dollar trail connecting Mr. Hussein to Mr. Bin Ladin has not been documented. If I were a member of the Bush Administration, this would make a better October Surprise than Mr. Bin Ladin's head on a pike. Conspiracy theorists take note.