You're basing your investment decision on a "what if" - and that's a huge if, US losing its dominance, where there's nothing to support this claim at the moment. This is like investing in Tesla, but not on their current EV business but their hypothetical flying car business which may or may not happen in the future..

So, a better approach might be to invest in today's facts (US being the dominance) and update your portfolio in the future if you see otherwise. i.e China, after an uprising, becoming a staple of democracy and freedom, allowing free flow of capital and thus replacing the US.

Otherwise you'd be missing a great deal of opportunity waiting on something else that far fetched to happen.