Ukraine has had a running conflict with Russia since the Orange Revolution pushed the former Soviet republic closer to the West. Gazprom, the state-owned natural gas producer in Russia, has occasionally threatened to cut off its supplies to Ukraine, even though the nation acts as a conduit to Gazprom’s European customers. After its latest action against Ukraine, they have responded by threatening to cut off Europe:

Ukraine’s natural gas company on Tuesday warned that if Russia further cuts its gas supplies, it could begin diverting shipments intended for western Europe.

Russia’s state-controlled gas monopoly Gazprom on Monday reduced shipments to Ukraine by about a third and on Tuesday threatened a further 25 percent cut if Ukraine did not resolve a dispute over debts and contracts by the evening.

Much of the gas that western Europe buys from Russia comes in pipelines that cross Ukraine. Gazprom has promised that gas destined for Europe would not be affected by the dispute.

But Dmytro Marunich, a spokesman for Naftogaz, Ukraine’s natural gas company, said the company “reserves the right to resort to adequate and symmetrical measures to defend the interests of its consumers.”

Only about one-quarter of the gas imported by Ukraine is of Russian origin; the rest comes from Turkmenistan and Kazakhstan in pipelines controlled by Gazprom. By raising the reduction above one-quarter, Gazprom apparently would be cutting the Central Asian gas as well as Russian-origin gas.

Gazprom wants to cast this as a collections issue, but few actually believe that. Gazprom’s CEO, Dmitri Medvedev, just won election to the Russian presidency, and his predecessor used Gazprom to punish Ukraine in the past. Vladimir Putin used to arrange these interruptions in supply at times when he wanted to impress on Ukraine leader Viktor Yushchenko how unhappy Russia would become if Ukraine continued drifting out of Moscow’s political orbit.

Even the collections piece has political origins. While Ukraine remained friendlier to Moscow during the Leonid Kuchma regime, Gazprom gave Ukraine “friend” pricing for its energy supplies. After the Orange Revolution, Gazprom attempted to impose a four-fold increase in the gas price, which led to Ukraine’s first siphoning project. That pricing dispute has never been fully resolved. An agreement between Yushchenko and Putin last month supposedly ended the dispute, but Ukraine’s Naftogaz has not yet formally agreed to the deal.

Europe will once again have to get involved in the Ukraine-Russia spat, which may be what Putin really wants anyway. He wants NATO to keep its hands off Ukraine and to stop the encirclement strategy that Putin claims has been in progress since Yushchenko chased Viktor Yanukovich out of the presidency. Is such a strategy, assuming it exists, worth the loss of Europe’s energy supplies? And who can least afford the interruption in gas sales — Europe, Ukraine, or Putin and Medvedev?