Where will they invest their money?
It isn't just "them" that have a problem of excess US$'s. Even US corporate balance sheets are flush with cash right now.
Where do you invest all that capital? Too much capital to invest is actually a great problem to have so long as inflation stays in check.
So where is the inflation that will destroy it all?
Your guess is as good as mine. Inflation will come eventually...But when? If you know the answer, you could be a rich man.