European officials have slammed Russia's decision to cut natural gas shipments to Poland and Bulgaria as "blackmail," claiming that the cutoff, as well as the Kremlin's threat to stop shipments to other countries, is a failed attempt to split the West over its support for Ukraine.

Russia's decision to use its most important export as leverage on Wednesday marked a significant step forward in the economic war of sanctions and counter-sanctions that has been waged in tandem with the combat on the battlefield.

The strategy used against the two European Union (EU) and NATO members might eventually force the targeted countries to ration gas, dealing a further blow to economies already struggling with rising prices. At the same time, it risks depriving Russia of vital funds for its military effort.

Poland has been a significant conduit for the sale of arms to Ukraine, and it announced this week that it will be deploying tanks to the country. Poland issued fresh sanctions against Gazprom and other Russian corporations and billionaires just hours before Russia's state energy behemoth acted.

Bulgaria has severed many of its previous relations with Moscow under a new liberal administration that took office last November, and it has also backed punitive measures against the Kremlin. Western fighter jets have also been stationed at a new NATO facility on Bulgaria's Black Sea coast.

The gas restrictions do not put the two countries in immediate dire trouble. Poland, in particular, has been striving for years to secure alternative supplies, and the continent is approaching summer, making gas less of a necessity for households. Furthermore, Russian gas deliveries to Poland and Bulgaria were set to halt later this year.

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