Pro-Russia militants mark the Donetsk and Lugansk regions' declared independence from Ukraine. Photographer: Alexander Khudoteply/AFP/Getty Images
Pro-Russia militants mark the Donetsk and Lugansk regions' declared independence from Ukraine. Photographer: Alexander Khudoteply/AFP/Getty Images

Among those who died fighting in Donetsk this week were Russian citizens -- at least eight, according to the city’s mayor. With that revelation, Russia’s involvement in the violence in eastern Ukraine is no longer in question.

The confirmed presence of foreign fighters exposes as untrue repeated claims by Russian President Vladimir Putin and Foreign Minister Sergei Lavrov that they are merely horrified bystanders to events in eastern Ukraine. Those claims were never plausible, given Russia's record in Crimea and thin popular support for the secessionist rebels in the east.

Lavrov recently challenged those who insisted Russia was backing the rebels to produce a single captured Russian agent. Of course, he can maintain that the Russian citizens killed in Donetsk were simply volunteers motivated by attacks on their ethnic kin in Ukraine. The eight, however, included Chechens, who by no stretch of the imagination are Russian nationalists.

There are certainly Chechen mercenaries available for hire, but they also answer to Chechen strongman Ramzan Kadyrov, who is fiercely loyal to Putin. Kadyrov has denied sending anyone to fight in Ukraine, but in an otherwise hard-to-explain twist, he personally negotiated the recent release of two Russian journalists held by pro-Ukraine forces. It is inconceivable that Kadyrov would send fighters to Ukraine without Moscow's approval or, more likely, instructions.

This conflict is following a script more than 20 years old: Russia intervenes in its ex-Soviet neighborhood using “volunteers,” including Chechens, and unmarked Russian military equipment to provide deniability.

Although transparent, Russia’s subterfuge is useful. It provides Europe’s leaders cover to avoid imposing costly economic sanctions on Russia. Putin withdrew troops from its border with Ukraine just before Sunday’s election there, the failure of which German Chancellor Angela Merkel had set as a trip wire for broader sanctions. European Union leaders who met on Tuesday were plainly relieved that they would not have to follow through on her threat.

However, the clash in Donetsk demonstrates that Ukraine’s presidential election alone will not stabilize the country. The decision by the city's separatist leaders to declare martial law and send troops to seize the airport the next day showed they saw the vote as a starting pistol to renew hostilities rather than a signal to de-escalate.

The Donetsk airport serves the region and is a vital piece of infrastructure. If separatists gain control of it, they could receive supplies and even reinforcements from aircraft arriving from Russia or other parts of the former Soviet Union. As it stands, border controls on cargo and passengers are in the hands of authorities in Kiev.

President-elect Petro Poroshenko’s rapid decision to order airstrikes to retake the airport demonstrated that the new regime intends to fight back. It, too, sees the vote as an occasion to reinvigorate its military effort. Poroshenko is gambling that Russia has decided against an open invasion, perhaps the only move that would trigger economic sanctions from the EU.

He may be right. But there's no doubt Russia is working to destabilize Ukraine. This campaign began with the annexation of Crimea, and the facts suggest it will continue until Putin gets the relationship with Ukraine that he wants.

Merkel’s threat of broad economic sanctions needs to be kept on the table. France should cancel its unconscionable contract to sell helicopter carriers to Russia. Countries participating in Russia’s South Stream natural gas pipeline project, which would allow Russia to send gas to Europe without using Ukraine’s pipelines, should pull out.

Ukraine has a new president. Little else has changed.

To contact the editor of this article: Marc Champion at mchampion7@bloomberg.net.

To contact the editor responsible for this article: Lisa Beyer at lbeyer3@bloomberg.net.