America's sheer size and influence dominates the world. Even in fields that are not of concern to the rest of the world, countries tow the line to keep this gorilla happy.
True - none of our politicians are going to take on the gorilla. It would only hurt them and us. So if it wants the gorilla gets to set the rules for everyone else - vote or no vote.
That is a self fulfilling prophecy. It is quite ironic that a European company has devolved to committing fraud to try to get around stricter emission rules in the US.