The plot doesn't make sense on countless levels.

-- Step One: The Evil Bush Conspiracy/Lizard People want to start a war.

-- Step Two: Evil Minions sneak into two giant skyscrapers and somehow wrap its internal structure with complex demolition systems without the thousands of people working there every day noticing it.

A real building demolished with these techniques has most of its internal non-loadbearing structure stripped out, leaving open beams everywhere. Charges are placed in many locations, and a forest of wires connects them to detonation equipment. This isn't the sort of thing you can do by making a two-inch access hole in a wall panel after the cleaning ladies leave and filling it in before morning. It would be like putting a second floor on top of somebody's house while they're living in it without them suspecting.

Still, assume they succeed.

-- Step Two and a half: Some idiot with a plate in his head proposes simply blowing up the buildings at this point and leaving clues implicating Middle Eastern terrorists. How hard could that be? He is laughed out of the secret lair. What kind of evil villain would do something so straightforward?

-- Step Three: Make a deal with terrorists to fly airplanes into the buildings and blow themselves to hell while the Evil Bush pushes a red button to collapse the towers. The terrorists ask them why the hell they don't just listen to the guy with the plate in his head? The Evil Bush promises wealth. "And how do we spend it as a pile of ashes?" wonder the terrorists. One terrorist points out, somewhat uncharitably, that you could start a really good war by simply arranging for the president to get assassinated.

After a week of waterboarding, the terrorists agree to commit suicide for no particular reason.

-- Step Four: The Evil Bush Conspirators wait in glee while the terrorists spend almost two years working their way into the U.S., taking flight training, and preparing for the day when they can commit suicide for no particular reason. Apparently, nobody's in a real hurry for this war.

-- Step Five: The plan unfolds. If it fails at any point, or the building is hit at the wrong level, or missed entirely, it won't work. And then, the Evil Bush would have to blow up the buildings himself. This would look very strange after the planes missed, so if the plan is still going to work, there are two choices: Either plant the clues that would implicate the terrorists up front, which makes the whole airplane plan look really stupid (that's the guy with the plate in his head doing an end zone dance at the other end of the lair) or sneak back into the building and remove all the charges before some maintenance crew finds them.

A masterpiece of thinking. Dr. Evil, eat your heart out.