Strongmen in Turkey and Hungary Stall Unity in NATO and the E.U.

BRUSSELS — Europe’s effort to stand up to Russia and Vladimir V. Putin, its president, is being slowed by two strongmen leaders insisting on the priority of their national interests and playing to domestic audiences.

President Recep Tayyip Erdogan of Turkey on Wednesday blocked a procedural vote on NATO moving ahead quickly with the membership applications of Sweden and Finland, handed in with much publicity Wednesday morning, a senior European diplomat said.

And Prime Minister Viktor Orban of Hungary continues to block even a watered-down European Union effort to put an embargo on Russian oil, part of a sixth package of sanctions aimed at Moscow for its war against Ukraine.

While NATO and the European Union have shown remarkable unity in their response to Mr. Putin’s war, the actions of the two authoritarian leaders show the strains building as the war drags on, peace talks appear to go nowhere, and Western sanctions are contributing to economic pain and high inflation at home, as well as in Russia.

Mr. Erdogan and Mr. Orban may be outliers in their organizations, but they are able to use the requirement for consensus in both NATO and the European Union to get their political concerns addressed by blocking the action of all the others, even temporarily.

On Wednesday, a meeting of NATO ambassadors could not reach consensus on a first vote to proceed with the requests for membership because Turkey said it first wanted NATO to address its security concerns. In particular, Ankara wants Finland and especially Sweden to end what Mr. Erdogan has called support for “terrorist organizations” in their countries, primarily the Kurdistan Workers’ Party, or PKK, as well as to lift export bans on certain arms sales to Turkey.

Turkey’s decision to block consensus came hours before the Turkish foreign minister, Mevlut Cavusoglu, was set to meet with Secretary of State Antony J. Blinken in New York; Turkey wants its security concerns to be addressed before NATO’s annual summit meeting in late June.

In an address to his lawmakers in Parliament on Wednesday, Mr. Erdogan criticized at length Western support for Kurdish groups that Ankara sees as a terrorist threat.

“It wouldn’t be wrong to say that we are bittersweet watching the solidarity and cooperation in the region, the sources used, the arms opened, the tolerance shown,” he said. “Because we, as a NATO ally who struggled with terror for years, whose borders were harassed, big conflicts occurred just next door, have never seen such a picture.”

Turkey “asked for 30 terrorists,” he said. “They said: ‘We are not giving them,’” Mr. Erdogan told the Parliament. “You won’t hand over terrorists but you want to join NATO. We cannot say yes to a security organization that is devoid of security.”

The PKK is a Kurdish guerrilla group that has fought a decades-long separatist insurgency in parts of Turkey. It was designated by the United States as a terrorist organization in 1997.

Mr. Erdogan remains angry over support from Washington and Stockholm for a PKK-affiliated militia in Syria, where the group was fighting the Islamic State. His government last year rebuked the United States and Sweden over the matter. And Turkey has demanded the extradition of six alleged PKK members from Finland and 11 alleged PKK members from Sweden.

Mr. Erdogan has said these issues cause him not to have “favorable thoughts” about the membership of the Nordic countries. But he has not said that he would veto their applications.

On Saturday, Ibrahim Kalin, Mr. Erdogan’s spokesman and foreign-policy adviser, said: “We are not closing the door. But we are basically raising this issue as a matter of national security for Turkey.”

National security is Mr. Orban’s argument, too. Hungary is dependent on Russia for its energy, getting 85 percent of its natural gas and 65 percent of its oil supply from Russia, as well as using Russian technology for its nuclear power plants.

While Hungary has approved all previous sanction packages, including an embargo on Russian coal, Mr. Orban proclaimed that an oil embargo would be the equivalent of an “atomic bomb” for the Hungarian economy.

But like Mr. Erdogan in NATO, Mr. Orban this time is the sole holdout, in his case, in the weekslong E.U. efforts to finalize a gradual embargo on Russian oil, the headline measure in a sixth package of sanctions since the invasion of Ukraine.

Talks began in mid-April. After extensive consultation between E.U. officials and diplomats from the bloc’s 27 member states, a proposal was put on the table incorporating different positions in early May.

But Hungary seemed to be moving the goal posts. The first proposal gave extensions to Hungary and Slovakia so they could find alternative suppliers. While the other 25 E.U. members would have until the end of the year, Hungary and Slovakia would have until the end of 2023.

Then Hungary demanded, and secured, even more time. The latest version of the package would grant it until the end of 2024, but Mr. Orban has insisted that Hungary would need billions from the bloc to shield his nation’s economy. His foreign minister, Peter Szijjarto, said that to use different oil and modernize Hungary’s energy system would cost between 15 billion and 18 billion euros and take five years.

Hungary’s block on an E.U. oil embargo, breaking unprecedented unity in punishing Russia, was well-received in Moscow. Dmitri Medvedev, Russia’s former president who currently serves as deputy chairman of the country’s national security council, said Mr. Orban’s opposition to the oil embargo was “a courageous step for voiceless Europe.”

In a post on his Telegram channel on May 6, Mr. Medvedev wrote: “Apparently, the most sensible leaders of the E.U. countries are tired of moving quietly to the precipice along with the entire sterilized European herd being led to the slaughter by an American shepherd.”

Diplomats said that they expected Mr. Orban eventually to acquiesce to an oil embargo, having secured both a long extension and extra funding for Hungary, but that he could drag the talks out even longer, perhaps until the end of the month when leaders are due to meet in person in Brussels to talk about Ukraine.

NATO officials expressed the same confidence about Mr. Erdogan — that he will eventually agree to back Sweden and Finland joining NATO in return for some concessions that will help him politically at home, with his economy in crisis and new elections only a year away.

Alexander Stubb, a former Finnish prime minister and foreign minister, said that “the Finns are cool and collected and so are the Swedes — this will work out.”

In the end, he said, “this is about security in Europe and about strengthening the alliance, and both Finland and Sweden are strong advocates of Turkish membership in the European Union.”

In 1999, he said, it was the Finnish presidency of the European Union that opened the door for Turkish accession, “and our friends in Ankara will remember that.”

Sauli Niinisto, the president of Finland, said in Stockholm that the Turks “have communicated to us from many sources that Turkey would not block membership.” A fast process is still possible, he said.

Jens Stoltenberg, the NATO secretary-general, said on Sunday, “Turkey has made it clear: Their intention is not to block membership. Therefore, I am confident we’ll be able to address the concerns that Turkey has expressed in a way that doesn’t delay the accession process.”

At least not too much.

Carlotta Gall contributed reporting from Kharkiv, Ukraine; Benjamin Novak from Budapest; and Johanna Lemola from Helsinki, Finland.