Strategy Page has a fascinating post with some operational details of the recent al Qaeda attack in Saudi Arabia. There aren't any permalinks, but the post I'm referring to was made on September 1st, 2003.
In the aftermath, several things became obvious. First was that the Al-Qaeda attackers used men on foot to force the gates. This had not been done in the past. The other two attacks, on the US Army headquarters of the Saudi National Guard Modernization Program and the Khobar Towers bombing, car or truck bombs had been used, but there was no associated ground assault.This is why it's important to knock out terrorist leaders (as Israel is doing when dealing with Hamas), rather than treat terrorism as a law enforcement issue and intercept individual terrorist acts. Leadership and coordination are what win wars, and if we want to win the War on Terror we must dismantle the infrastructure and the intellect that supports it.