He's Australia's most decorated soldier. Now he's at the centre of a historic war crimes case

One of the most significant moments in Australian military history unfolded without fanfare on a tarmac at Sydney airport, when Ben Roberts-Smith was calmly escorted off a plane and into a waiting police car.

The country's most-decorated living soldier and the most famous of his generation, Roberts-Smith was on Tuesday charged with five counts of the war crime of murder.

It follows a high-profile civil defamation case, which three years ago found that the former Special Air Service (SAS) corporal and Victoria Cross recipient had unlawfully killed several unarmed Afghan detainees.

Roberts-Smith, who left the Australian Defence Force (ADF) in 2013, denies all wrongdoing and says the allegations are "egregious" and driven by spiteful and jealous peers.

His case – now set to be tested to a higher, criminal standard – has become the face of Australia's reckoning over the country's alleged conduct in Afghanistan, which has cast a pall over its much-mythologised military legacy.

"For Roberts-Smith to now be charged with war crimes - and not just one, but multiple war crimes - is a very significant cultural and social moment for a country that, for much of its history… has placed a lot of store in the exploits and contributions of the members of its defence forces," Professor Donald Rothwell told the BBC.

But the prosecution of such a highly-decorated veteran is also an extraordinary moment for the globe.

"We've never seen this before," says Deane-Peter Baker, a special forces ethics scholar.

When Roberts-Smith came home from Afghanistan in 2013, he was considered a national hero, having been awarded Australia's highest military honour for single-handedly overpowering Taliban fighters attacking his SAS platoon.

Plum speaking engagements and board gigs, magazine covers and massive portraits, accolades and awards – like Father of the Year – followed.

But in 2018, Nine newspapers began publishing a series of articles alleging misconduct during his time with the SAS – claims of unlawful beatings and killings of prisoners, bullying of colleagues, and domestic violence against a mistress.

He said it was all untrue, and in a bid to clear his name, launched a high-profile legal battle. It spanned seven years, cost millions of dollars and was dubbed by some as Australia's "trial of the century".

He lost. While the claims of domestic violence and some of the bullying allegations were dismissed, a Federal Court judge in 2023 ruled the reports he committed four murders were substantially true, a judgement that was upheld on appeal.

Roberts-Smith now faces even higher stakes if convicted of the five charges against him: life in prison, and an unwelcome place in history.

Victorian Cross recipients from other Commonwealth nations have faced criminal charges, but Roberts-Smith is believed to be the first charged with a war crime.

"If you expand the lens and consider recipients of equivalent awards in other countries, you would be very hard pressed to find one who has been charged with a war crime," says Baker, who reformed the ADF's ethics training after scrutiny over its record in Afghanistan.

Roberts-Smith's arrest was the culmination of a five-year investigation by a special watchdog set up after a landmark inquiry into allegations of Australian war crimes in Afghanistan.

The 2020 Brereton Report found "credible evidence" that elite soldiers unlawfully killed 39 people, recommending 19 current or former ADF members be investigated.

A specialist team, called the Office of the Special Investigator (OSI), was set up to do so – but progress has been slow.

The OSI has launched 53 investigations, 39 of which have been finalised. It has charged only one other person so far, former SAS soldier Oliver Schulz.

Ross Barnett, director of investigations at OSI, on Tuesday said they were confronting "challenging circumstances" – which include limited preserved physical evidence and no cross-border policing cooperation.

"The OSI has been tasked with investigating literally dozens of murders alleged to have been committed in the middle of a war zone in a country 9,000km from Australia," he said.

"We can't go to that country, we don't have access to the crime scenes... we don't have photographs, site plans, measurements, the recovery of projectiles, blood spatter analysis... we don't have access to the deceased. There's no post-mortem."

Adding another layer of complexity, is the onus that places on witness testimony from so-called "brothers in arms".

Though it was a handful of Roberts-Smith's peers who surfaced the allegations against him, getting members of the military to testify against each other goes against informal norms, Peter Stanley - former principal historian at the Australian War Memorial (AWM) - told the BBC.

"Military culture is a really important factor in this," he said.

"[But] potential witnesses who may otherwise have been silent have come around to the idea that their principal obligation is to the truth, and not to any friendships they may have."

It's unlikely to be a coincidence that the two cases which have progressed to court were both the subject of investigative reporting, he adds, which may have revealed leads for police and helped smooth the path to prosecution.

Barnett told reporters Roberts-Smith's arrest is a "significant step", but the OSI is committed to completing its remaining investigations "expeditiously".

But the formal judicial process is unlikely to be swift either.

"We have no contemporary experience of war crimes trials being conducted in Australia," says Rothwell, one of Australia's leading experts in international law.

"This is novel in terms of modern Australian legal history."

The nature of the alleged offences aside, Roberts-Smith's case poses an array of other challenges for the legal system.

There are five distinct charges, all of which relate to events some time ago – and with each one, comes a mountain of evidence.

Then there's the logistical difficulty of coordinating witnesses, some of whom may need their identities protected for safety or national security reasons, as well as some who are based in Afghanistan and with whom communication is near impossible under current conditions.

There is also the quandary of dealing with the troves of potentially prejudicial information already on the public record, which includes fair and accurate reporting of the 110 days of evidence presented in Roberts-Smith's civil defamation case.

In rare cases, a judge alone may preside over a trial in Australia, but if the case is heard before a jury, finding one oblivious to Roberts-Smith will be a challenge.

"Inevitably it will somewhat muddy the waters," Rothwell says.

All of that, factoring in general delays in Australia's legal system as well, means a trial is "most definitely" years away, Rothwell says.

Schulz, for example, was charged in March 2023 with a single count of murder, but will not face trial until next year.

Australia has long supposed that its troops are the kind you want to be fighting alongside, but also fighting against: effective, hardy, brave and loyal while being fair and ethical.

The values of the so-called Anzac spirit - famously traced to a doomed offensive carried out by Australian troops at Gallipoli, Turkey, in World War One - are embedded in Australia's sense of national identity.

But this drawn out saga is challenging the way the nation sees itself and its forces.

Surveys have indicated it is damaging to the general public's faith in the defence force, and that it is a source of distress for members of the ADF.

What adds to the anxiety is the pace of the investigations - organisations such as the Returned Services League say it has been unfair to all involved including the families of the alleged victims in Afghanistan.

"It must be galling for [those] who are facing these allegations, and indeed present members of the Defence Force who may feel that their service is being impugned," Stanley says.

But he argues it would be far more painful if investigators got this wrong, Stanley says.

"It would be tragic if they were to launch charges prematurely or to not make the clearest and most effective case."

Sections of Australia, though, question whether these inquiries and prosecutions are a worthwhile pursuit.

Among them are Australia's richest woman Gina Rinehart and former prime minister Tony Abbott, who said his "instinctive sympathy" remained with special forces soldiers from the Afghanistan campaign.

"I am very sorry that some of them have been subjected to a form of persecution by the country they served," he said this week.

For others, the fact that Australia is showing leadership on these issues is a source of comfort. Other countries, like the UK, have announced their own Brereton-style inquiries into allegations of misconduct.

"In a weird way, this is a moment that Australians should be proud of," Baker says.

"For a nation to hold a member of their armed forces to account - someone who has been held up as one of our greatest living heroes – shows a commitment to ethics, decency and the rule of law that is unfortunately very rare among nations."

"That ought to be recognised and applauded, however embarrassing or sad this is for many people," Stanley adds.