[narby]

it would be much easier for a lone terrorist to fly a small plane into a building than to obtain 20 ton truck

Really? How many terrorist pilots are there? How many terrorist drivers are there?

The truck place is called "U-Haul", and they don't even require the two hour check-ride to rent.

[Man50D]

The truck place is called "U-Haul", and they don't even require the two hour check-ride to rent.


You ignore the fact a lone terrorist would also have to obtain all the necessary ingredients to fill the large number of barrels a 20 ton truck could contain. It's reasonable to assume a 20 ton truck can carry many barrels. The terrorist would have to purchase large quantities of whatever ingredients needed to fill those barrels. It would be at the very least difficult if not impossible for any individual to purchase such large quantities without being noticed.

The only possible way to remain conspicuous would be to purchase small quantities over an extremely long period of time but he would have to store these ingredients somewhere. The terrorist would then run the risk of being noticed constantly delivering the same ingredients that can be used in combination as explosives to a storage area. He would then have either have to place empty barrels in the truck and lift all the necessary ingredients into the truck by himself or fill the barrels outside the truck and then lift the barrels with some device such as a fork lift. He would have to rent fork lift which could be expensive, take more time and attract more attention.

Contrast that with a small plane. The terrorist would take a few courses, fill the gas tank and load as much explosives the maximum weight of the plane allows and then fly the plane.

The latter maths requires much less manual labor.

Keep trying to think.