The negative ramifications seem to be better than being invaded by the US or having regional entities invaded by the US, and the ensuing instability as a result.
If its going to be like this the rest of the world might as well cut its losses
You seem to have a very limited view of the world if you think the US doesn't have fans of totalitarian rule and that the "rest of the world" is exclusively against US global strategy. I am going to guess that you actually have no idea what the negative ramifications of the collapse of a currency that underpins the foundations of our world are, because it is something that is near impossible to predict.
I agree that at some point, governments and people will need to step up and fight back, but the idea that the US will somehow fall in a vacuum and everyone else will live happily ever after is laughable.
If its going to be like this the rest of the world might as well cut its losses