In theory this sounds like it might work, but in practice any international reserve/settlement currency will see more inflows than outflows. This will cause tha

In theory this sounds like it might work, but in practice any international reserve/settlement currency will see more inflows than outflows. This will cause that currency to appreciate, which by itself is a deal-breaker for many countries. A good case study is pre-Euro Germany. It had all the ingredients of a secondary reserve currency and was in fact used as such. However the appreciation that resulted from those inflows was not wanted at all since it didn't fit with the export-oriented economic model and made exports noncompetitive. As a result German capital markets were never opened to foreigners to the same degree British or American markets are. While being the world's reserve currency is undoubtedly an "exorbitant privilege" in some respects, it also has many drawbacks. I don't think India or China would be willing to issue Bonds to foreign entities at the volume that the US is doing.