You touched on a subject I thought about many years ago.
First a little background -MPC is Military Payment Certificate money it looks like monopoly money.
Upon arriving in Korea you had to turn in all your greenbacks and get the equivalent in MPC.
When I was in Korea for months, all of a sudden they told us to turn in all our MPC money immediately, like, by noon the next day.
The Army then reimbursed you with the equivalent of the new MPC.
This had the effect of defrauding anyone outside of the military that had large amounts of old MPC. The old MPC became worthless, and could never be turned back in for Greenbacks.
So I got to wonder what if a country decides to default and has its citizens turn in their money for a new currency issue and the outsiders get stuck with useless money.
I realize it gets messy and there are a lot of considerations like letting selected friendly countries, or countries you depend on, off the hook.
Pretty complicated, and probably a straight up default on selected debts is the easiest option.
But the way the world is going, nothing can be ruled out.
Just wondering. - Tom
Quick currency change scenario was assessed in case of Greece, when there was a serious risk they will have to be kicked out of Euro Zone (and get back to own currency) and it turned out that just the logistical part of it (like printing new banknotes etc.) would take weeks and involve so many people that it won't be possible to keep it a secret... and that could cause panic, run on the banks etc.
Besides, cash these days is for us, little people and even we use it less and less... For banks and big business basically only digital records... which would have to be converted into new currency, else no one will trust and accept the new currency and that would cause an economic suicide. So that's an option only for some 4th world shytholes. I think North Korea did something similar several years ago, they basically stole most of savings of their own people (who else use their currency?) setting old money/new money exchange rate like 4 to 1 or something.
In case of Russia, I don't know where $1.5 trillion comes from. Their total external corporate debt is like $150 billion... If they decided to default on that, assets of their companies outside of Russia would be seized and they would be out of international financial markets for a long time. In short that would cause far greater damage to Russia than to anyone else.