Opponents of an agreement to change Macedonia’s name to the Republic of North Macedonia protest in Skopje on June 23. (Boris Grdanoski/AP)

PRESIDENT TRUMP may believe that NATO is obsolete, but Vladi­mir Putin clearly doesn’t. The Russian ruler remains motivated to take extreme and sometimes self-defeating measures to stop any expansion of the alliance, as an unlikely spat between the Kremlin and the normally Russophilic government of Greece demonstrates.

The trouble started in June, when after decades of dispute the left-wing Greek government of Alexis Tsipras finally reached an agreement with Macedonia, whose name Athens has disputed since it became an independent nation a quarter-century ago. In exchange for its neighbor’s adoption of the name the Republic of North Macedonia, Greece agreed to lift its objection to the tiny Balkan state’s accession to NATO and the European Union. Both organizations have since promised to open membership talks with the Macedonian government, provided the new name is ratified in a September referendum.

Macedonia is smaller than Maryland, has a population of just 2 million and is bordered on three sides by NATO members, so its accession to the alliance ought to be both logical and of scant concern to Moscow. Yet the Putin regime launched an ugly campaign of bribery and subterfuge to stop it. According to Greek authorities, Russia tried to pay off Greek clerics and officials to oppose the deal; according to Macedonia’s prime minister, Moscow funneled hundred of thousands of dollars to NATO opponents there, including soccer hooligans who were paid to stage violent demonstrations.

The meddling prompted Mr. Tsipras’s government to expel two Russian diplomats this month and deny entry to two others, while accusing the Putin regime of “constant disrespect for Greece.” That was a remarkable rebuff from a government that has been one of Russia’s best European friends: Athens had previously refused to punish Russia for the poisoning of a former spy and his daughter in Britain and argued against other Western sanctions. Moscow responded by canceling a planned visit to Athens by Foreign Minister Sergei Lavrov, and the two capitals continue to trade angry statements.

Here it’s worth noting that Macedonia is not to be confused with nearby Monte­negro, another tiny country that joined NATO in 2017 and that Mr. Trump ludicrously suggested last week might be the trigger for World War III. It happens that Mr. Putin also mounted a clandestine intervention to stop Monte­negro’s NATO accession, backing a coup plot there in 2016. That gambit also backfired, but Mr. Putin apparently hasn’t moved on: Mr. Trump’s ignorant claim that Montenegrins were “very aggressive” probably was planted at last week’s Helsinki summit.

Mr. Putin has had remarkable success in inducing Mr. Trump to promote the Kremlin’s interests and parrot its agenda, including its goal of weakening and eventually fracturing NATO. But the blowup over Macedonia is a reminder that, in his zeal to restore Russia’s superpower status, Mr. Putin has frequently overplayed his hand. With or without Mr. Trump’s help, Macedonia probably will join NATO. And despite the machinations of Mr. Putin and his White House friend, our bet is that the alliance will outlast both of them.