War veterans will rally on Saturday in support of Victoria Cross recipient Ben Roberts-Smith, whose arrest prompted some to say it is 'Vietnam repeating itself'.

Many veterans fear Roberts-Smith's high-profile arrest will alienate the next generation of Australian soldiers in the same way those returning from Vietnam were treated 50 years ago.

Roberts-Smith was taken into custody at Sydney Domestic Airport after arriving on a flight from Brisbane on Tuesday morning.

He was charged with five counts of war crime - murder in relation to alleged incidents in Afghanistan between April 2009 and October 2012, after a joint investigation between the Office of the Special Investigator (OSI) and the AFP.

The arrest has sparked fierce debate across Australia.

Former commando and SMEAC veterans charity spokesman Peter Richards will rally with other veterans today alongside vocal Roberts-Smith supporter Pauline Hanson in Queensland. 

'It is not just Ben Roberts-Smith who has been dragged through the dirt here, it is every soldier who fought in a war the Australian public does not understand,' he told News Corp.

Hanson vowed to stand by Roberts-Smith in the wake of his arrest as she slammed authorities over the huge cost to reach this stage.

'I remain steadfast in my support,' the senator posted online.

'Ben, his immediate and broader defence family need the Australian people's support right now and I will not abandon him like so many other politicians.'

Former SAS Association national chairman Martin Hamilton-Smith claimed the Roberts-Smith case had been mishandled by successive governments since the Brereton Report found evidence of war crimes in 2016.

'This is Vietnam repeating itself. An unpopular war. The politicians and the senior generals who helped design it have walked away. And we're now blaming corporals and sergeants for things that may have gone wrong in the war that politicians and generals designed,' he said.

'We lost the war. We all saw the exit from Kabul, just as we lost Vietnam and we saw the exit from Saigon.'

Australia's richest person Gina Rinehart joined Hanson, slamming the arrest of Roberts-Smith, saying in a statement: 'I don't understand how it can be justified to spend more than $300million to try for years to bring SAS veterans, who have served our country, towards criminal proceedings, and most recently the arrest of Ben.'

'As the recently passed Brigadier George Mansford succinctly stated, "The oath to serve your country did not include a contract for the normal luxuries and comforts enjoyed within our society". On the contrary, it implied hardship, loyalty and devotion to duty,' Ms Rinehart said.

Former navy clearance diver John Armfield feared the Roberts-Smith case could set a dangerous precedent that will affect future recruitment.

'They see soldiers being investigated years later, which is appropriate if evidence supports it. But they also see unresolved questions about leadership, decision-making, and accountability at higher levels,' he said.

Coalition defence spokesman Phillip Thompson claimed veterans had 'lost any trust' in the government.

Meanwhile, displays honouring Roberts-Smith at the Australian War Memorial will remain on show, despite calls from some historians to remove them from the Hall of Valour.

They will remain at least until criminal proceedings against the accused war criminal are settled.

Roberts-Smith's uniform, medals and combat helmet remain on display in the Hall of Valour, which honours recipients of the Victoria Cross.

'Whatever the truth is, whenever the truth is known, we will tell it,' Director of the Australian War Memorial Matt Anderson said.

'The most important thing all of us can do now is let justice take its course.'

Senior lecturer in Australian history at the University of NSW Michael McKernan, who was the deputy director at the museum in the 1990s, told the Sydney Morning Herald that keeping Roberts-Smith's uniform display up was 'ludicrous'.

'You can't leave it there. It's ludicrous. He is now charged with five murders. Let's get real – that's not good,' he said.

UNSW Canberra Professor Peter Stanley, formerly the Memorial's principal historian, told Daily Mail: 'My position is clear and simple. The Roberts-Smith display should be moved out of the Hall of Valour into the Afghanistan gallery, so his story can be portrayed as one of the tragic consequences of Australia's involvement.'