TORONTO — Jack Letts has never lived in Canada. He has visited — seven times, by his count — and has family here.

But he was born and raised in England, and as recently as February told reporters he considered himself British.

Still, he also has Canadian citizenship, through his Ontario-born father. And now he wants to come “home.” Which is presenting a problem for Prime Minister Justin Trudeau.

Letts, 24, traveled five years ago to Syria, where he is alleged to have joined the Islamic State. He was captured by the Kurds in 2017, dubbed “Jihadi Jack” by the British media, and is among the thousands of suspected foreign fighters being held in Kurdish prisons in northeastern Syria. The Kurds are pushing their countries to take them back.

Letts was mostly Britain’s problem, until July. That’s when the government of Theresa May, in its final days in office, quietly revoked his citizenship. Now he’s only Canadian — news that was made public here this week, just as Trudeau faces a difficult election in October.

Soon after Trudeau was elected in 2015, his Liberal Party repealed a law passed by its Conservative predecessor that allowed the government to strip the citizenship of dual nationals convicted of terrorism-related offenses in Canadian courts.

“A Canadian is a Canadian is a Canadian,” he had said during his campaign. “And you devalue the citizenship of every Canadian in this place and in this country when you break down and make it conditional for everyone.”

Opposition leader Andrew Scheer, whose Conservative Party is in a dead heat with Trudeau’s Liberals, has sought to make Letts’s fate an election issue: He promised this week that a Conservative government would not “lift a finger” to help Letts.

Trudeau, asked this week whether he was open to bringing Letts to Canada, didn’t respond directly. He said instead that Canada would continue to prosecute those who leave the country to support or participate in terrorism. Trudeau’s government has been reluctant to repatriate citizens who have joined terrorist groups abroad.

The case has brought new attention here to a long-simmering dilemma for officials in Canada and other countries: What should they do with their citizens who traveled to the Middle East to join the Islamic State? Do they have obligations to repatriate dual citizens who weren’t born in their countries?

The quandary has grown more acute this year as U.S.-backed Kurdish forces declared military victory over the Islamic State, taking over the final pockets of the group’s self-declared caliphate in Iraq and Syria, and sweeping up a flood of fighters, their wives and children — many with foreign passports — into camps and prisons in Syria, where their futures are uncertain.

The detainees include at least 33 Canadians, including nine women and 18 children, according to Amarnath Amarasingam, a professor of religion at Queen’s University in Ontario who has visited the camps for his research. Conditions in the camps are poor, he said, and many women and children are malnourished, diseased and dying.

In their public comments about Letts, Canadian government officials have focused largely on their anger at Britain for revoking his citizenship.

Public Safety Minister Ralph Goodale said Canada was “disappointed” that Britain “has taken this unilateral action to offload their responsibilities.”

John McKay, the Liberal lawmaker who chairs the Canada-United Kingdom Inter-Parliamentary Association, called the decision “gutless.”

“It was kind of like, ‘Let’s go out the door and leave Canada with a problem,’ ” he said.

There are reasons beyond politics that governments are reluctant to bring their foreign fighters back. Law enforcement officials might have difficulty gathering evidence needed to prosecute the returnees for crimes committed in foreign war zones. Officials fear they might not be able to detain returnees, leaving them free to radicalize others or carry out attacks at home.

“Canada has a history of not being good at taking information derived from the intelligence community and using it in prosecution in a criminal court,” said Leah West, a lecturer in national security law at Carleton University in Ottawa.

Still, she said, Canada has prosecuted war crimes. Investigators could interview detainees being held at the camps to obtain evidence.

“It would require extra effort,” she said. “But given the nature of the offenses, it would be worth it.”

Goodale said Canada has charged and convicted four returnees with terrorism-related offenses since 2015.

If Canadians returning from Syria couldn’t be prosecuted, Amarasingam said, the government could surveil them.

Prosecuting Letts would pose additional challenges, West said. Because he traveled to Syria from Britain, Canada could not charge him with leaving Canada to facilitate terrorist activity. Instead, prosecutors would have to prove that he committed a terrorist-related offense in Syria.

Letts’s father, John, and his mother, Sally Lane, say their son is innocent. In June, a British court convicted both of funding terrorism by sending money to their son to help him escape from Syria. They were given suspended prison sentences.

John Letts told the Canadian Broadcasting Corp. this week that his son, a convert to Islam, traveled to Syria for “humanitarian and religious reasons.” He said his son was under duress when he told reporters he had joined the Islamic State, and John Letts accused Canadian lawmakers of “abdicating their responsibility.”

Goodale said that the government has “no legal obligation” to facilitate the return of Letts or other Canadians detained in Syria. He said the region where Letts is being held is too dangerous for consular officials to visit.

McKay, the Liberal lawmaker, said there’s “not a heck of a lot of sympathy” for Letts, particularly because his ties to Canada are “remote.” He called Letts’s Canadian status “a citizenship of convenience.”

Letts told reporters from ITV News in February that he was homesick. Asked whether he felt more British or Canadian, he said, “I feel British. I’m British.”

This week, after being told he had been stripped of his British citizenship, he appeared to have had a change of heart. He told ITV News that he always felt he was “a mix,” and he didn’t think having British citizenship was “a big deal.”

“My whole family is Canadian,” he said. “I have no relatives in Britain anyway. Everyone’s in Canada.”

Some national security analysts say the Canadian government’s inaction carries risks. It’s better to bring foreign fighters home where they can be monitored, the analysts reason, than take the chance that they escape and carry out attacks elsewhere or become radicalized in prison.

“ISIS got its start in 2003 in a camp,” said Stephanie Carvin, an international relations professor at Carleton University. “These camps are breeding grounds for an ISIS resurgence.”

Carvin said Canada could amend its evidence laws to address some of the barriers to prosecuting returnees. In Australia, for instance, the government can declare it illegal for its citizens to travel to certain designated zones, which is an easier evidentiary threshold for prosecutors to meet.

Canada, Amarasingam said, has a moral responsibility, particularly to the children.

“As a first-world, developed country, if we can’t help repatriate and provide counseling for 18 children, that’s a pretty bleak thing to kind of argue.”