Say, India wants to buy weapons from Russia, Russia is under American sanctions, and America doesn't want this deal to happen so it says the transaction, as long as it's in dollars, won't be authorized by America. How is it possible?
I mean if I have dollars and I want to buy something as long as the seller is happy with being paid in dollars, setting the issue of legality of using a currency that is not legal tender aside for the moment, no one can stop this deal. Certainly not America, if I'm not America.
What exactly changes when you advance to high-end deals? Can't India simply wire the needed amount of dollars to Russia? Or even move it physically, in bags?