You're being too general, in my opinion. Piracy is almost completed stopped just by presence, not by combat. American also engages in and their taxpayers fund foreign wars, which perhaps it should stop doing, but that is very separate to economically bouying up a global economy via and global R&D via global grant awards and open sharing of American research findings. Trump is right now pausing NIH funding and detaching from the WHO. All the funding that paid for benefited other countries is now gone, partly because people globally laughed at America for not spending enough on its citizens, and eventually enough of its citizens didn't think it was worth keeping on doing that any more.