EXPLAINER: What's next for Europe's natural gas during war?

Russian President Vladimir Putin is demanding payment in rubles for natural gas — or else

Russian President Vladimir Putin is demanding payment in rubles for natural gas — or else. Germany is talking about gas rationing in case of a cutoff. Prices for the fuel used to heat homes, generate electricity and power industry are through the roof.

There's a lot of discussion around natural gas in Europe against the background of Russia's invasion of Ukraine, to say the least.

Here are key things to know:

WHAT IS PUTIN PROPOSING?