Should convicted terrorists be stripped of their home country's citizenship?

Last September, Hiva Alizadeh, an Iranian-born Canadian, was arrested with a partially-assembled bomb in his possession. Alizadeh, who became a naturalized Canadian citizen in 2007, had trained in Afghanistan with insurgents related to the Taliban, and pled guilty in September to possessing an explosive substance with intent to harm. He is currently serving a 24-year prison sentence.

This week, Canadian authorities began the process of stripping Alizadeh of his Canadian citizenship, under a new law that allows the Canadian government to revoke citizenship to those convicted of terrorist offenses. It’s the first time the government has used the new law, known as the “Strengthening Canadian Citizenship Act.” And it raises a tough question for the U.S. and other nations whose citizens will soon be coming home from places like Syria and Iraq: should convicted terrorists get to keep their citizenship?

According to the Canadian law, citizens who are convicted under terrorism, espionage, and treason charges can have their Canadian citizenship removed and can be deported after they finish their prison sentence, as long as they have dual citizenship in another country. (The law can’t be used on people who are only Canadian citizens because it would leave them stateless, violating international law.) Meanwhile, Australian legislators are considering an even broader citizenship revocation law, and the United Kingdom expanded its own citizenship-stripping law last year.

Proponents of these policies say they’re an effective way to punish terrorism. “Canadian citizenship is a privilege that carries both rights and responsibilities,” Kevin Menard, a spokesman for Canada’s citizenship and immigration minister, told Fusion in a statement. “Dual nationals who commit the most serious crimes, those who seek to harm Canada and Canadians, will face serious consequences: we will move to revoke their Canadian citizenship.”

But some legal experts worry that revoking citizenship because of a terrorism-related conviction may be overreaching. Audrey Macklin, a University of Toronto law professor, says the law is an example of using immigration policy to try to solve terrorism problems. Especially since 9/11, anti-terror policies have done things to foreigners “that would have been unthinkable or illegal if they were done to citizens,” she told Fusion. “But not everyone who is seen as presenting a security threat is not a citizen.” And because Canada’s policy only applies to people who are also citizens of another country, it “suggests that dual citizens are considered lesser citizens,” she said.

Paul Slansky, a lawyer who is challenging the citizenship law in Canadian courts, told Fusion that he planned to appeal the case potentially to the Supreme Court. “If you’re born here, you’re by definition a citizen, period. The government has no authority to legislate or take that away,” Slansky said.

There is also the question of what, exactly, constitutes a terrorist act. In Australia, legislators introduced a similar bill last week that would strip Australian citizens who fought in terrorist groups of their citizenship—but its wording is so broad that it could apply to much lower-level offenses, such as damaging government property, legal experts say.

The two former British colonies are following in the footsteps of the United Kingdom, which expanded its decades-old citizenship-stripping law in 2014. The UK measure requires only that the home secretary finds the decision “conducive to the public good,” with no public hearing and little court oversight. Prime Minister David Cameron has publicly worried about Britons in ISIS from coming back home, and he’s already used the citizenship-stripping law more often than all previous governments since World War II combined.

The laws play into the larger global war on terror, and, some say, perpetuate its abuses. Mohamed Sakr, a British-Egyptian who was born and raised in London, was stripped of his citizenship in 2010 under suspicion that he was a member of the al-Shabab terrorist group. A year and a half later, he was killed by a U.S. drone strike in Somalia.

Another former British citizen, Bilal al-Berjawi, was also killed in a drone strike in January 2012 after his citizenship was revoked. “If they had UK citizenship when it had happened, then the UK would have had to take an interest in them,” Macklin said.

The commonwealth countries aren’t the only western nations that are revoking citizenship. France, for example, stripped a French-Moroccan man of his citizenship after convicting him under terrorism charges in 2013. That decision was affirmed by the country’s top court this year.

Some conservatives want to see the U.S. adopt similar policies. Texas Sen. Ted Cruz, who’s running for president, introduced a bill last year that would remove the citizenship of Americans who join, fight for, or give “material assistance to a designated foreign terrorist organization that is working to attack the United States or its citizens.” (His campaign did not respond to a request for comment.) Former Sen. Joe Lieberman proposed a similar bill in 2010.

But those efforts would likely run into legal problems. The Fourteenth Amendment to the Constitution protects the rights of citizens, and the 1967 Supreme Court case Afroyim v. Rusk found that a U.S. citizen could not have their citizenship be revoked involuntarily.

“It’s flatly unconstitutional in the U.S.,” Temple University law professor Peter Spiro, who wrote a book about citizenship, told Fusion.

Even though it may not be constitutional to strip an American citizenship involuntarily, Americans should still expect to hear plenty about it in the months leading up to the 2016 election. “This makes good political theater,” Emily Berman, a University of Houston law professor, told Fusion. “Ted Cruz is running for president and wants to establish his tough-on-terrorism bona fides, but I don’t think they’re really viable legislative proposals that are bound to go anywhere.”