Many people in the US have a chip on their shoulder about the US taking even a tiny bit of friendly advice from the rest of the world.

When John Kerry mentioned the need for global consensus in one of the presidential debates, George Bush pounced and Kerry immediately tried to back off.

That is the political reality in the states when it comes to outside influence. Even a hint of it, from the best of friends, is not tolerated.

Their governments could try (citizens likely wouldn't be able to), but we've seen how that's worked in the past. The only countries who can change US policy is China and Israel.