In Syria, the last holdout of Islamic State is finally being overrun. The so-called caliphate, once the size of Britain, attracted supporters from around the world, including from Australia, but has now been reduced to a small enclave on the Iraqi border. Those remaining – including some of the movement’s most vehement adherents – are surrendering, or being captured or killed. As the fighting ends, Australia will need to decide how to deal with its Islamic State exiles.

It may be hard to sympathise with those who have participated in the Islamic State’s depravities and who continue to condone them, yet the status of these expats – despite the equivocating of Scott Morrison and Peter Dutton – is clear: they are Australian, and it is in Australia that they should, if necessary, be prosecuted and rehabilitated.

Since 2012, according to Australian security agencies, about 230 Australians have travelled to fight for extremist groups in Iraq or Syria. Of these, about 40 have reportedly returned to Australia, about 90 have been killed, and about 100 remain abroad. The Australian Federal Police has so far issued at least 27 arrest warrants for Australians fighting overseas. 

The Australians who joined Islamic State include fighters and so-called “ISIS brides”, such as Zehra Duman, who left Melbourne in 2014 and married fellow Australian Mahmoud Abdullatif, who died in Syria in 2015. Duman has used social media to call for attacks on Australians, and has expressed hope that Syrian children would die as martyrs.

The home affairs office says the Australian government wants to deal with such people “as far from our shores as possible”. This puts Australia at odds with Donald Trump, who has urged countries to take back the surviving Islamic State fighters and their families. This week the US embassy in Australia told Nine Media that it believes countries such as Australia should prosecute and rehabilitate its own citizens to ensure they pose no further threats.

But Australia’s policy, like that of Britain and New Zealand, is to revoke the citizenship of terrorists – if they are dual citizens and revocation does not render them stateless. In itself this policy is problematic: it abrogates a country’s responsibility to look after its own citizens, and raises questions about how local authorities can conclude that an untried expatriate is a terrorist. And Morrison has gone further. He has proposed new laws that would allow the home affairs minister to revoke the citizenship of convicted terrorists if the minister is “reasonably satisfied” they are dual citizens. Labor opposed the move and believes it is unconstitutional.

The consequences of the proposed change were evident from Dutton’s bungled handling of the case of Melbournian Neil Prakash, a convert from Buddhism to Islam who called for attacks in Australia before being captured by Turkish forces at the border of Turkey and Syria in 2016. Dutton revoked Prakash’s Australian citizenship, declaring that he was a citizen of Fiji via his Fijian father. However, Dutton apparently failed to check with Fiji’s government, which said that Prakash was not a Fijian. Prakash recently told a court in Turkey that he did not mind his Australian citizenship being revoked because he did not want to be extradited to face charges. The court in Turkey sits again on Friday. Prakash could soon be freed, regardless of whether he poses a threat to public safety.

The preferable approach for Australia is to take back these misguided fanatics, ideologues and radicals – many of whom had records of crime and misadventure in Australia – and to try them for any offences they committed overseas. Australia has passed various terrorism-related laws that could apply to these expatriates, and though it may be hard to collect evidence and prove crimes committed in war-torn Syria, dealing with them on Australian soil has multiple benefits. It would help to deter other potential foreign recruits. It would mean Australia fulfils its international obligations and could encourage other countries to do the same. And it would address the security concerns of Trump and others, ensuring these expatriates – many of whom have not renounced their support for the caliphate or for terrorist attacks in the West – do not remain a threat. The caliphate is in tatters, and Australia should stand by the system of rules and order that these expatriates were seeking to tear down.