> the US still has enough pull that it could probably get most western nations to march in line

The US absolutely could coerce the rest of the West in the short term, but everything that's happened in the last decade calls the long-term future of Atlanticism into serious question and such action would accelerate this process I think. If coordination came as an order from Uncle Sam, it would be seen not as a legitimate act of ensuring collective safety but as mere technological imperialism on America's part.