Their actions did. Supply and demand and what happen if you suddenly refuse to buy from your major supplier without alternative ready to fill the difference? That’s pretty obvious to anyone so if they did it, that’s their responsibility.
Europe did not refuse to buy gas from Russia. Russia just stopped selling gas to Europe.
They did for months. Russia was blocked from the SWIFT system which was used for the international transactions, mostly in euro and dollars. So Russia could literally not sell anything because it would not get paid. So they wanted to get paid in rubles and even set up exchange accounts in Russia in order to do so. Several EU countries did it, like Hungary, Bulgaria and Italy. Only after months of naked hostility and economic warfare Russia refused to trade, small wonder considering EU is openly declaring itself enemy to Russia.
