Russian President Vladimir Putin signed a decree on March 31 requiring "unfriendly" countries to pay for Russian gas in rubles or face supply disruptions. Due to Europe's dependence on Russia's natural gas, the decree could be seen as a "trump card" used by the Kremlin to counter sanctions and a key step by Russia to boost its currency value. What is Europe's next step? In this episode of BizBeat, CGTN's Song Yaotian explains.