So a newly elected Vice President of the US decides to have a meeting with some buddies who had been big campaign contributors. The buddies are all hotshots in the oil industry, and they have a very cordial, but secret, meeting. While the meeting is acknowledged, the VP declines to reveal what was discussed.
All the hotshots go home and assure their close colleagues that the oil industry will get some special privileges from the new Administration, including (don't tell anyone) additional access to Iragi oil, and down the road more favorable terms from the Saudis and Iranians. The Iraqi deal that had given the French and Russians access to Iragi oil would be thrown out the window, since the Iraqi regime was in for a big change. Getting our own puppets in Iraq, with their agreement to put US military bases there, would give us big leverage against Saudi Arabia and Iran.
A couple of the folks who attended the meeting couldn't restrain themselves. One just had to let out a little bit of the secret to help drive a harder bargain with a Saudi oil services company. Another couple just had to impress the boys at the bank with their secret knowledge about something big that was just over the horizon that was sure to lift profits.
You can probably guess what happened next.
It didn't take long for the rumors to reach the elites of Saudi Arabia. Some skeptics ignored them, but others took them seriously and pieced together a good idea of the big picture. Realizing the constraints against direct action, they looked for proxies who would disrupt the American plans. Enter Al Qaeda, a willing proxy, with a couple of good plans already taking shape. The rest, as they say, is history.