Back in the early 1900s, dual citizenship was considered undesirable by many countries.
It was common for Australian women to be stripped of their citizenship if they married a foreign man, and Americans could have theirs revoked for simply voting in a foreign election.
But over time, politicians have come to understand the detrimental effects that losing citizenship can have on a person even if they remain a citizen of another country.
Courts in both the US and the idea that losing citizenship is a severe punishment and should not be arbitrarily enforced.
In more recent years, dual citizenship has become popular among many Australians using their ancestral links to secure foreign passports, allowing them to zip through immigration lines at airports and work in other countries.
Despite its appeal, some politicians have been eager to crack down on dual citizens, including in Australia, as a way of blocking undesirable persons from returning to the country.
This week, Opposition leader Peter Dutton raised the idea of to change the constitution so ministers would be allowed to remove Australian citizenship from a dual national if they committed certain crimes.
While the current laws allow a minister to request citizenship be stripped from an individual, it is the court that makes the decision and it only does this during sentencing for specific crimes such as terrorism or treason.
Australia is not the only country reassessing the loyalty they expect from their citizens.
Tech billionaire Elon Musk is facing calls for his Canadian citizenship to be stripped over his alleged efforts to "erase" the nation's sovereignty as part of United States President Donald Trump's government. .
Tesla CEO Elon Musk is a top adviser to US President Donald Trump. In a now-deleted post on X, he mocked a petition calling for his Canadian citizenship to be revoked, saying: "Canada is not a real country." Source: AAP / Jae C Hong/AP
Meanwhile, in wants to change the constitution to strip citizenship from anyone considered a "threat to public order".
The amendment is part of a broader anti-immigration campaign by Orbán's authoritarian government, targeting billionaire philanthropist George Soros, who is a US-Hungarian dual national and prominent supporter of liberal causes and civil society in his homeland.
The privilege of citizenship
Unlike those born in the US, people born in Australia are not automatically granted citizenship.
The US constitution enshrines a right to citizenship in its 14th amendment, but in Australia, it's the politicians who dictate eligibility.
Those who have taken the path to citizenship can attest it is often hard-fought, requiring years of living in Australia with limited financial support — even if the person is married to an Australian.
Once becoming a citizen, people have the right to vote in Australian elections, get an Australian passport, and enter and remain in the country.
In return, they are asked to take an oath to "pledge my loyalty to Australia and its people, whose democratic beliefs I share, whose rights and liberties I respect, and whose laws I will uphold and obey".
The value of citizenship has also been tested when Australians get in trouble overseas. The government has, including Julian Assange, Cheng Lei and Sean Turnell.
WikiLeaks founder Julian Assange returned to Australia in June 2024 after walking free from a US court. Source: AAP / Rick Rycroft/AP
Helen Irving, a professor emerita of constitutional law at Sydney University, says: "Australian women who married foreign men automatically lost what was [then] their British citizenship, merely by the act of marrying a foreign man."
This had a "harsh and detrimental" effect on many women's lives, she says.
In America in the 1940s, Irving says all sorts of conduct could lead to the stripping of citizenship, including living in another country for five years or taking up a government position in a foreign state.
But by the 1960s, the understanding of the character of citizenship had changed, and the US Supreme Court ruled that stripping citizenship was such an extreme measure that it amounted to punishment.
Losing citizenship is a 'very severe loss'
Australia has also upheld the view that losing citizenship is tantamount to punishment.
In recent years, Australian politicians have tried to strip citizenship from those who travelled overseas to join terrorist groups such as the self-proclaimed Islamic State group in Syria.
Laws introduced in 2020 allowed the relevant minister to strip citizenship from someone who had been convicted of an offence and sentenced to at least three years imprisonment if they were satisfied the person had repudiated their allegiance to Australia and it was contrary to the public interest for them to remain a citizen.
But those sweeping powers have since been moderated: an appeal brought before the High Court of Australia in 2022 found politicians did not have the power to remove citizenship once it had been granted.
This is because of the prevailing view that stripping citizenship is a punitive act and should, therefore, be determined by a judge when sentencing criminal offences.
You lose effectively your right to return to your country — and quite rightly — the court says this is a very severe loss.Professor Emerita Helen Irving
"Being banished, being exiled from one's own country, which means losing your sense of your place in the world, as well as your association with your family and your upbringing — that very close, important, existential tie that a person has with their own country."
In recent years, New Zealanders who have been forced to leave Australia due to controversial visa changes enacted in 2014 have spoken of the isolation they felt at not being able to live in the country they called home for decades.
Larice Rainnie, 72, was deported in 2019 after her visa was cancelled following an 18-month jail sentence for a drug-related crime in Finland. She had previously lived in Australia for 55 years.
Larice Rainnie spent most of her life in Australia but was deported to New Zealand in 2019. Source: SBS News / SBS News/Amelia Dunn
But in other countries like the United Kingdom, government officials have the power to take away a person's citizenship if they consider it conducive to the public good.
Separation of powers
In Australia, changing the constitution to allow ministers to revoke citizenship — as has been proposed by Dutton — could give significant extra power to politicians.
One of the foundations of Australia's democratic constitutional system is the separation of powers between the legislature (the parliament), the executive (the prime minister and ministers), and the judiciary (the courts).
Irving says this system protects people from being arbitrarily punished because those accused of crimes have their guilt determined by a judge or jury, "not at the say-so of powerful individuals".
If we had government able to name people as 'guilty' and imprison them or deal with them however they wished, the liberty that people enjoy would be very much reduced.
While Dutton's proposal has opened up debate around the rights of dual citizens, former immigration official Abul Rizvi does not think any government will go back to restricting dual citizenship.
"The two biggest cohorts of dual citizens are likely to be Brits and Kiwis. No government will want to anger them," he tells SBS News. "We now live in a very mobile world where people like to have two or more passports. It's more convenient."
Census data shows more than half of the population in Australia is either born overseas or has at least one parent born overseas.
A spokesperson for Amnesty Australia has described Dutton's proposal as an "extreme and reactionary proposal that will have dire, far-reaching consequences", noting that it is emblematic of Dutton's for personal political gain.
"Dutton's deportation plan would be particularly dangerous for citizens who have fled war, persecution and conflict and found asylum in Australia."
— Additional reporting by AFP
