The side that was hit was separated from a closed private parking lot that was 50 feet away and to get there would have meant going through a guard post.
IF you ever visited the Pentagon you would know that a car bomb would have been placed on the other side, where the road goes right up to the 10 feet from the door for buses etc.
the story was made up by a French communist who hated the USA.
I worked at the Pentagon a lot during the late 80’s-early 90’s doing electrical work. Pre 911 the guard posts were a joke. Several of our trucks were cleared to drive into the basement areas. I remember times, like when we needed extra men to pull wire for instance, we’d meet in the parking lot, put a few extra guys in the bed (under cap) of a pickup truck, and just drive them in to avoid the red tape of “getting them cleared” when we only needed them for a day or two. The guards were used to us coming in every day and just waved us through.
No doubt that all changed after 911, but I remember back then, as a young apprentice, thinking how easy it would be if you were a bad person to do nasty stuff there.