[webinarian]

But many countries are buying the green backs and trades are done in US dollars.

Actually, contrary to what you said, the use of USD is decreasing, not increasing.  

Russia sold all it's US debts. Iran is having 25 year agreement to sell oil to China in RMB. A few other countries are switching away from using USD such as Venezuela, and other M East countries, such as Saudi.  

As RMB turned into digital, more could be using digital currency.