The way I (state certified smoothbrain) think of it is this: Cash reserves serve as short time collateral when a state is shopping on credit (which states usually do). So your transactions need to be backed by a currency your trading partner is willing to accept.

Other types of reserves exist, but these usually need to be converted first, which adds a layer of delay and transaction that makes it a more long term thing.

Not sure how correct it is, but I find that this oversimplification works and is correct most of the time.

Such things happen when one decides to start a money burning competition with a block of countries with a combined GDP roughly 25 times that of russia.

I often see the argument “Which part of your country would you be willing to cede in the name of peace?”

Normally this would be a valid argument, but in trumps case, I’m sure he’d gladly cede California or some other blue state if it meant he gained something from it. He has no scruples or integrity, and thinks other heads of state are the same.