Sweden’s dedication to free speech is complicating its drive to join the North Atlantic Treaty. Two weeks ahead of a NATO summit, the government allowed an Iraqi migrant to protest by burning a Koran in front of a Stockholm mosque Wednesday, a Muslim holiday.

On the second day of the Muslim holiday Eid-al-Adha, hundreds gathered outside a mosque in Stockholm to witness a man tear up and burn Islam’s holy book after receiving a green light from the police under freedom of speech principles. Turkey, which has blocked Sweden’s bid to enter NATO, is now accusing the Nordic country of disrespecting Islam. 

Ankara has long considered demonstrations against Islam and in favor of Kurdish rights in Sweden to be an affront to its tenets. Turkish officials say the country is harboring members of a terrorist group, the Kurdish Workers’ Party, or PKK. Ankara wants members of the group exiled to Sweden to be extradited to Turkey before it will sign off on Sweden’s NATO membership.

Following protests at Stockholm in January, the Swedish police rejected several applications for anti-Koran demonstrations. In mid-June, though, an appeals court rejected the police argument that such protests make Sweden a “higher priority target for attacks.” The permit for the protest was given in accordance with the right of free speech, the Swedish police said. 

Some 200 people witnessed one of the two protest organizers, Salwan Momika, tear up pages of the Koran, wipe his shoes with them, and put bacon in it, before setting the book on fire. Counter-protesters shouted “God is great” in Arabic, expressing their disapproval of the burning. The police detained a man who attempted to throw a rock at the organizers. 

Mr. Momika said that his intentions were not to sabotage Sweden’s NATO bid and that he even considered waiting to protest until after the country’s membership had been confirmed. “I don’t want to harm this country that received me and preserved my dignity,” Mr. Momika told the Swedish newspaper Aftonbladet in April. 

In his protest application to the police, Mr. Momika said he wanted to protest in front of a large mosque in Stockholm and “express my opinion” on the Koran by tearing and burning it up. The protester also told Swedish news agency TT that he wanted to emphasize the importance of freedom of speech. “This is democracy. It is in danger if they tell us we can’t do this,” Mr. Momika said.

“On the first day of Eid-al-Adha, I curse the despicable act committed in Sweden against our Holy Book, the Holy Quran!” Turkey’s foreign minister, Hakan Fidan, tweeted Wednesday, adding that it is “unacceptable” to allow this under the pretext of freedom of expression. “To condone such atrocious acts is to be complicit,” he says.

Sweden’s prime minister, Ulf Kristersson, says he will not speculate how the Wednesday event could interfere with its NATO application process. “It’s legal but not appropriate,” he said during a press conference. 

In a statement, the Stockholm mosque has condemned the event “in the strongest possible terms” and expressed a “deep disappointment” with the police. The mosque notes that about 10,000 people, including families with children, frequent the mosque during the Eid prayer.

Sweden and Finland applied to join NATO in May 2022, months after Russia invaded Ukraine. Mr. Kristersson said on Wednesday he expects to join the alliance before or even at the NATO summit at Lithuania’s capital, Vilnius, on July 11. 

While Stockholm’s application is supported by nearly all members of the organization, including America, Turkey and Hungary have blocked Sweden’s admission. Any expansion of the organization must be agreed to by all of NATO’s 30 members. 

Anti-terrorism legislation came into force last month in Sweden, which will “close a loophole in our already existing anti-terrorist legislation” and clear the way for joining NATO, Stockholm’s foreign minister, Tobias Billstrom, told the press. 

Ankara was unimpressed. Sweden’s change of terrorism laws is “meaningless” as long as groups such as the PKK are allowed to freely protest in the country, President Erdogan of Turkey told NATO’s secretary-general, Jens Stoltenberg, on Sunday. 

The left-wing PKK, which has fought for independence from Turkey, but now promotes rights for Turkish Kurds, is designated as a terrorist group by America, Turkey, and Sweden. 

The leader of a Danish far-right political party, Rasmus Paludan, who also has Swedish citizenship, burned a copy of the Koran near the Turkish embassy at Stockholm in January. At the same time, a group of demonstrators protested against Sweden’s NATO application and expressed support for the Kurds in the capital. They carried a banner that read: “We are all PKK.”