People are not sure it was a plane that hit the pentagon...

[Chojin]

It's really cute that people with no understanding of physics try to argue this from a 'common sense' point of view, but unless you actually have some experience, do please shut up. For example, it's illegal to throw crap off the empire state building because even a penny dropped from that height is fatal to anyone below. Just because in your limited experience pennies bounce when they hit the ground (even when you throw them at it really, really hard) doesn't mean that they don't sink an inch or two into concrete when enough inertia is behind it.

Same thing with the pentagon. If you fired a sparrow at the speed of sound in the general direction of the building, it'd do some damage.

As for this great debate, I don't get why it matters what hit the pentagon. It wasn't the primary target and in the grand scheme of the aftermath means all of jack and shit. You don't see 9/11 NEVA FORGET shirts with pictures of a burning pentagon next to a morbidly-depressed eagle. The World Trade Center attack was the only one that really mattered as far as public opinion goes.

So, here are your two scenarios:

1. America is attacked by terrorists who hijack 4 planes, 3 of which hit targets in the US.
2. America is attacked by terrorists who hijack 4 planes, 2 of which hit the trade centers, 1 of which vanishes, and the president calls in an attack at the last minute to fire a missile at the pentagon 'just to be safe'.