A sanction alternative against Russia that would bite so hard that the country backs out of the war of aggression against Ukraine, say those who want it introduced.
This is because Russia's large revenues from oil and gas sales abroad would freeze inside when they can not pay.
But it also costs money for those countries that need to buy oil and gas from Russia, such as Germany.
In addition, Russia has previously created its own Swift-like system.
In the short run it hurts - in the long run the profit is more murky.