How did you arrive at this kind of hypothesis? How are you sure that Russian Ruble will be gone forever when they are still maintaining their exporting strength in different goods including wheat. They can just restrict the use of other currencies in dealing with their export goods. A countries currency may easily go into extinction if they are not producing or manufacturing countries but if they are, it won't be easy to push them by the side, they can activate their currency allegiance while buying or exchanging for their export products.