These days, there are few realms where Russia and Ukraine do not find themselves at odds.
So it was again at this weekend's Eurovision contest, a kitschy annual song competition whose founders intended it to be a cross-cultural unifying force in post-World War II Europe.
This year, Russia's early favorite Sergei Lazarev was ultimately topped by Ukrainian entry Jamala, who sang "1944," about the brutal Stalin-era expulsion of the Crimean Tatars – including Jamala's great-grandmother – from what is now Russian-annexed Crimea.
Jamala's win cued predictable controversy, with Australians complaining that their entry had stronger support from the voting professional jury than Jamala and Russians claiming that public voting favored Mr. Lazarev, who was allegedly derailed by pro-Ukrainian jurors. Russian lawmakers are already warning they might boycott next year's contest, which Ukraine would host as this year's champion.
But a deeper problem is the reason "1944" is so controversial in the first place. Why do Russians continue to feel stung by references to the Stalinist uprooting of national minorities accused of collaborating with the Nazis, such as Crimean Tatars and Chechens? Especially when it was carried out by the USSR, a regime that disappeared a quarter of a century ago.
Ignored in Ukraine
That's in part because post-Soviet Russia never really publicly aired Stalinist crimes, and under Vladimir Putin the Kremlin has been actively reviving nostalgia for the former superpower and its great achievements, such as the victory over Nazi Germany.
The Crimean Tatars who survived expulsion to Soviet central Asia were gradually allowed to return to Crimea from the 1980s, says Alexei Makarov, a historian with the Memorial human rights group. But they found their former homes and lands occupied by hostile Russians and Ukrainians, and no backing from authorities to reestablish themselves.
"The authorities of newly independent Ukraine declared that they were building a democratic state, but in practice did nothing to solve the problems of Crimean Tatars," he says. "That left them to squat on plots of land [in their traditional areas] where they had no legal status. The Crimean Tatars insisted they were restoring historical justice, but Ukraine pretended not to see this problem because the crimes had been carried out by another state, the USSR."
Ironically, it was only last year, after Russia's annexation of Crimea, that the Ukrainian parliament officially recognized the Soviet-era treatment of Crimean Tatars as "genocide."
Accused in Russia
But the new Russian authorities in Crimea have moved to actively crack down on the Crimean Tatars, first by closing down the only Tatar-language broadcaster and, last month, banning the Mejlis, the self-governing body of Crimean Tatars, as an "extremist" organization.
Russian legislation now makes it a criminal offense to call for the return of Crimea to Ukraine.
Russia accuses Ukraine-based Crimean Tatar groups of carrying out acts of sabotage, such as earlier this year cutting the electricity pylons that provided power to the peninsula.
The few reliable polls to be done inside Russian-annexed Crimea appear to show that majorities of ethnic Russians and Ukrainians on the peninsula are generally satisfied with the transfer to Russian control, but Tatars remain largely disaffected.
Russian authorities insist that they are moving to address the social and economic demands of Crimean Tatars, while separating them from the influence of "extremist" leaders whom they claim are associated with Islamist and Ukrainian nationalist forces.
"Relations between Russia and the Crimean Tatars remain very tense," says Mr. Makarov, which helps to explain the raw nerve struck by Jamala's Eurovision victory. "On the whole, the Russian authorities have created an environment of terror [for Tatar activists in Crimea], with constant searches and interrogations. This is not a problem that will go away anytime soon."