The government’s mooted legislation to tackle returning foreign fighters will undoubtedly make it easier to detect and prosecute those involved in terrorism overseas. This means many returned fighters (and supporters) are likely to enter the legal system and potentially end up in prison.

But beyond the hype of the immediate threat, scant attention has been paid to how we might manage these individuals once they enter the correctional system.

Should we segregate or even isolate terrorist offenders from mainstream inmates to prevent prisoner radicalisation? Or should we disperse them among the rest of the prison population? So far, Australia’s experience with terrorist offenders in isolation shows that the government hasn’t got it right.

As The Sydney Morning Herald recently noted:

Almost a decade after their arrest, much of the most comprehensive terrorist cell in Australian history continues to menace the country.

Khaled Sharrouf, for example, who recently rose to international notoriety for his barbarous activities in Iraq, served time in Goulbourn’s maximum security jail. He was imprisoned for his role in the 2005 plot to blow up the Holsworthy army barracks. Released in 2009, Sharrouf was unchanged by his time in prison. One could argue that his time in prison made him worse.

Correctional services have managed terrorist inmates since the first arrests in 2005 and, later, following the prosecution of participants in the Pendennis and Neath terrorist plots. These terrorist offenders were deemed “high risk”. They were initially isolated from other inmates at Goulburn jail’s high-risk management unit in NSW and at Barwon Prison’s Acacia high-security unit in Victoria.

In Goulbourn jail, terrorist offenders were categorised “AA” as part of a 2004 NSW government initiative that established a security classification appropriate to the terrorism threat. This strategy is partly designed to prevent radicalising others by minimising human contact, reducing time out of cells for exercise, limiting prisoner contact, and restricting access to communications, visitors and reading material.

Isolation in maximum security facilities has a long history in prison management and is used to exert control over “high-risk” prisoners. It is controversial; the evidence is unequivocal that it can impact on the mental and physical health of inmates.

For terrorist offenders, incarceration can reduce their chances of rehabilitation. It may increase disruptive behaviour, as well as enhance the likelihood of recidivism. Isolation can also reinforce the psychology of exclusivity and “martyrdom”, and may even foster or magnify the causes that led offenders to terrorism in the first place.

While both a psychiatrist and a judge cautiously believed that Sharrouf had abandoned his radical beliefs, it seems isolation only consolidated them. Having slipped out of the country last year to fight with Islamic State, Sharrouf is now one of Australia’s most wanted terrorists – along with Mohamed Elomar, whose uncle Mohamed Ali Elomar was Sharrouf’s co-accused in the Pendennis trial.

The terrorist offenders placed in Barwon prison following Operation Pendennis also had issues with isolation. Initially, 11 terrorist suspects were isolated from other prisoners in the Acacia unit and held there for at least three years while awaiting and attending trials. Conditions there were deemed by the Victorian Supreme Court to:

… pose a risk to the psychiatric health of even the most psychologically robust individual.

Close confinement, shackling, strip-searching and other privations had clearly added to the psychological stress of incarceration. As a result of that ruling, the Pendennis defendants were transferred out of high security to the Metropolitan Remand Centre.

In 2008, one of those defendants, Abdul Nacer Benbrika, was found guilty of leading and being a member of a terrorist organisation. Benbrika was initially held in high security but, following a risk assessment, was moved into a protective unit with other inmates (albeit under close supervision).

Due to Benbrika’s reputation as a fervent proselytiser, it was feared that he would radicalise other inmates. The outcome has been quite the opposite.

Until now, Benbrika has not attempted to radicalise others. He has, instead, had difficulty relating to a prison population that appears to look down on terrorist offenders, placing them somewhere near the bottom of the inmate code. Some inmates have tried to dissociate themselves from Benbrika for fear of being stigmatised.

Sharrouf or Elomar are unlikely to return to Australia. Yet we must think carefully about how we manage and treat those who do come home. And we must remember that the fighters’ offshore activities align more closely with violent criminality than terrorism. We should therefore think twice about automatically according all of them AA status and isolating them from other inmates.

Beyond assigning labels, evidence-based studies must also examine the most appropriate way to manage terrorist offenders. As Sharrouf’s example clearly shows, current strategies that isolate terrorist offenders have not worked.

However, we don’t yet know what works in Australia. Overseas examples, such as in the Philippines and the United Kingdom, suggest dispersing convicted terrorist offenders into mainstream prison populations may be better than isolating them.

When terrorist inmates are dispersed, powerful social and environmental pressures are brought into play that affect inmates in different ways. The pressures of adapting to a prison environment, for example, as well as the demands of the various dominant inmate social groups, are unavoidable factors in staying safe and fitting in.

Some terrorist offenders may never disengage or de-radicalise. They represent a higher risk than others. Each should therefore be judged on a case-by-case basis. For most, however, time in prison may bring about a transformation away from violent extremism – and could even prove a catalyst for positive change.

At the time of writing, prison sources suggest that the conflicts in Iraq and Syria may have re-energised some terrorist inmates. Whether Benbrika will try to radicalise others is yet to be seen. While this may raise alarm bells, very little evidence exists to suggest that those radicalised inside prison go on to commit terrorist acts upon release.