On 2022-04-27, the Russian state-owned energy company Gazprom has ceased gas deliveries to Poland and Bulgaria, after they refused to henceforth pay for the gas in ruble rather than the currency stated in the contract. Other EU countries and customers in those countries have also refused to pay for gas deliveries in ruble. For example, 97% of gas payments in the EU are in euro or dollar. Is there any factual difference that would explain why gas deliveries were stopped to (customers in) Poland and Bulgaria, but not to other EU customers? Or is this purely a political decision based on (semi-)opaque political considerations from the Russian Federation leadership?