If the Australian Federal Police were happy to arrest Ben Roberts-Smith at Sydney Airport in a way that became an instant public spectacle, then Australians are entitled to ask a simple question: what will happen if the so-called ISIS brides walk through the arrivals gate? 

Will they be subjected to the same treatment? And if not, why not?

Roberts-Smith isn't above the law. He has been charged with grave offences and, like anyone else, he's entitled to the presumption of innocence. The allegations against him will be tested in court.

But Roberts-Smith served this country in Afghanistan (on multiple occasions) and was awarded the Victoria Cross, the highest military honour Australia can bestow. Yet he was arrested at the airport in front of his family, with the humiliation made public almost immediately. 

Reports that he had been willing to surrender privately only make the spectacle even harder to justify. The 'lights, camera, action' nature of the arrest was completely unnecessary.

But that's the precedent the AFP has now set and vehemently defended. 

So if adult Australian women - who willingly entered the world of Islamic State - make it back here, they shouldn't be quietly processed, carefully managed and wrapped in bureaucratic caution. 

If the evidence supports their arrests, they should be met by the AFP at the airport and charged with every available offence that fits their conduct. 

And the media should be told about it in advance and the cameras should be rolling, just as happened to Roberts-Smith, with the authorities distributing the vision in the very same way.

If not, why not?

While many Australians might call the actions of the ISIS brides treasonous, more likely, prosecutors will look at foreign incursion offences, declared area offences, membership of or support for a terrorist organisation, or potentially crimes connected to the conduct of Islamic State itself.

That is for investigators, prosecutors and the courts to decide, assuming the brides make their way back here.

These women left Australia and entered territory controlled by one of the most barbaric terrorist movements of the modern era. 

Islamic State murdered, raped, enslaved and butchered its way across the Middle East. Any adult who knowingly attached themselves to that project should face the full force of Australian law.

Tanya Plibersek, to her credit, has been stronger on this than the Prime Minister. Anthony Albanese hasn't exactly been timid, to be fair, but he has been cautious. 

Plibersek went further, saying that if they return, they should be 'picked up at the airport' and face the full force of the law.

Bravo for saying what most Australians are thinking.

Given the long and loaded history between Plibersek and Albo inside Labor, it's hard not to think that she enjoyed the contrast between her sharp popular rhetoric and his more cautious, underwhelming commentary. 

It sharpened the government's position in a way the PM hasn't quite been willing or able to do. 

But words are easy, the real test is what happens at the airport.

The children, of course, will need to be treated differently. They aren't responsible for where their parents took them or the ideology they may have been exposed to, or born into. But the issue of indoctrination and subsequent security risks can't simply be dismissed for the kids either.

These ISIS brides weren't tourists who took a wrong turn - caught in the wrong place at the wrong time. If they knowingly travelled into Islamic State territory, remained there, supported the men who fought for it, helped sustain the organisation's operations, or raised children within its sick ideological world, they should be treated as a national security threat and dealt with accordingly.

Many Australians will rightly struggle to understand how they could get new passports to get back here in the first place. If the government can lawfully stop these women returning to our shores, as the opposition claims is possible, it should. But assuming Labor is right when it says that it's powerless to prevent the return of legal Australian citizens, and can't deny them new passports to do so, what it does next matters.

Australia has laws designed for precisely this kind of conduct, as outlined. The authorities should use them where the evidence allows for doing so, immediately arresting them the moment they land, in full view of the cameras.

Either airport arrests are acceptable public acts of law enforcement or they are not. If they were good enough for Ben Roberts-Smith, they are more than good enough for the ISIS brides.