Where was Insulate Britain during the US motorcade?

One question to ask. Why not now? Is it because Air Strip One has the real leader on the ground and the military would now not tolerate this kind of protest that would put the POTUS in potential harm's way?

There are people standing on the green watching, they look to be members of the public, so it would have been perfectly possible to have had blocked it.

I imagine the reaction of the US military that are in all of the other cars and vans, along with the attending UK military would have either been to run them over, to rip them from their glued paws on the floor, or to do something else.

History will not remember you like tank man.