No every, you just don't know it ;)

There was a recent case of one Serbian company being sanctioned by the USA, and Visa and Master refused to process payments. No big deal, since even a small country like Serbia has its payment system called Dina that kept the company afloat.

There's not a single technical reason for bigger and richer countries to develop their own card payment system. It's not rocket science. The only reason they didn't is their regulators wanted a dependency on the USA payment processors.