After decades of military non-alignment, Finland and Sweden submitted applications for N.A.T.O. membership on May 16^th. Russia’s invasion of Ukraine in February sparked widespread support for N.A.T.O. membership in Finland and Sweden almost overnight, reported Finnish broadcasting company Y.L.E. Acceptance into N.A.T.O. requires the approval of all 30 member nations. Though initially expected to be a fairly quick process, President Recep Tayyip Erdoğan of Turkey has threatened to stall the process until certain concessions are met. Turkey contends that Sweden, home to a large Kurdish diaspora, has not taken Turkey’s concerns over Kurdish terrorism seriously.

Turkey recently demanded that Sweden extradite 21 political dissidents accused of terrorism for their alleged ties to the Kurdistan Workers’ Party. Sweden refused, leading Erdoğan to tell the Turkish parliament, “We asked for 30 terrorists. They said: ‘We are not giving them.’ You won’t hand over terrorists but you want to join N.A.T.O. We cannot say yes to a security organization that is devoid of security.”

Erdoğan contends that Sweden supports P.K.K. and harbors P.K.K. terrorists. In addition to extraditions, Turkey wants a promise to crack down on media and fundraising of alleged P.K.K. affiliates in Sweden and Finland before it will consider approving their N.A.T.O. applications, according to the Wall Street Journal. Turkey also wants a lift on restrictions regarding selling weapons to Turkey.

Diplomats from Finland and Sweden are attempting to persuade Turkey to reconsider its objections, but Erdoğan has told them “not to bother,” according to Al Jazeera.

This puts Sweden in a difficult place. Turkey is adamant that greater commitment to targeting Kurdish terrorism is critical to ratifying Sweden’s, and by extension Finland’s, application to N.A.T.O. However, Sweden has a sizable Kurdish diaspora, with six members of its Parliament having Kurdish descent, and sympathy for Kurdish nationalism is high. Sweden will need to balance appeasing Turkey and supporting its Kurdish minority.

The Kurdistan Workers’ Party (P.K.K.) is a militant group, formed in 1984, which initially fought for an independent Kurdish state in southeastern Turkey and now seeks greater autonomy and rights for Turkish Kurds. Since 2015, when a two-year ceasefire ended, clashes between the Turkish military and the P.K.K. have killed nearly 6,000 people, according to International Crisis Group. The P.K.K. is recognized as a terrorist organization by Turkey, the US, and the E.U., which includes Sweden and Finland. In Iraq, the P.K.K. played a critical role in fighting ISIS.

Part of the issue stems from different classifications of the People’s Defense Unit (Y.P.G.). Turkey equates the Y.P.G. with the P.K.K. and accuses anyone involved in the Y.P.G. of terrorism. From 2014-2016, the Y.P.G. collaborated with U.S. military forces and their allies to combat ISIS in Syria, earning the Unit support in the West. “That the freedom fighters who have fought or sympathized with the Y.P.G./Y.P.J. or P.Y.D. are classified by certain state actors as terrorists is unacceptable,” Swedish Social Democrats party secretary Tobias Baudin wrote in response to Turkey’s demands.

The conflict between Turkey and Sweden shows larger friction in the N.A.T.O. allyship, all other members of which are prepared to expedite Sweden and Finland’s applications. Turkey, which once hoped to join the E.U., has become increasingly authoritarian under President Erdoğan and distanced itself from the West.

Although Vladimir Putin has threatened harsh retaliation against Finland and Sweden for joining N.A.T.O., most foreign affairs analysts as well as Finnish president Sauli Niinistö do not believe the Nordic nations are in any immediate danger. Expanding N.A.T.O. to Sweden and Finland would be strategically beneficial to N.A.T.O. Finland shares a lengthy border with Russia while Sweden controls an island in the Baltic Sea, intercepting Russia’s only waterway to mainland Europe. In the event of further Russian expansion into Europe, a military alliance with Sweden and Finland could prove critical for the security of both the Nordic region and the wider Western world.

Over the next few months, as N.A.T.O. member states approve Sweden and Finland’s applications, Sweden and Finland must show Turkey that they take Turkey’s security concerns seriously without compromising the Kurdish diaspora community and any peaceful Kurdish organizations.