(As an aside, I find it necessary to use this angle because Elkus and Haddick cover their topics incredibly well, so I really can't add to anything they've written. Well, except for in Adam Elkus' blog, where I posted a picture of a LOLcat.)
Certainly, ejecting Saddam Hussein from Kuwait was a just decision in 1991. Yet, in another example of how chaos theory seems to influence our foreign policy, the American presence in Saudi Arabia helped to sow the seeds of the September 11th attacks. After the Iraqi invasion, a young Saudi named Osama bin Laden, fresh from fighting the Soviets in Afghanistan, begged the royal family not to let non-Muslim troops into Saudi Arabia. Bin Laden offered to defend the Arabian peninsula with hjis Mujahadeen fighters.
When questioned how his Mujahadeen would stand up against tanks in the open deserts of Saudi Arabia--the optimal environment for such vehicles--bin Laden was reported to have claimed that he would fight the Iraqi tanks "with faith". Unfortunately, faith doesn't really hold up well against T-72s (though it is, admittedly, difficult to clean off the treads.)
His offer was rebuffed, and Western forces comprised the bulk of the military force during Operation Desert Storm. Bin Laden eventually traveled to Pakistan, where he began to focus his ire towards the West, and America in particular. And he continues to this day.
Critics of counterinsurgency doctrine often claim that a well-conceived foreign policy at the strategic level would preclude the use of American forces in counterinsurgency-style conflicts. Yet, as a wise man once said, "Always in motion, the future is". Few could have predicted that the defence of Saudi Arabia would kick-start a chain of events which would eventually give rise to a figure like Osama bin Laden.
Indeed, Black Swans and Butterflies are everywhere.