The moving commemoration to mark 50 years since the withdrawal of the last Australian troops from Vietnam was almost certainly the last chance to honour so many surviving veterans on such a scale.
Time has dramatically thinned the ranks of the estimated 60,000 troops deployed to South Vietnam between 1965 and 1972.
Within the next decade and a bit they, like the veterans of the Boer War, the two world wars, Korea, and the Malayan insurgency, will have marched into history.
But, like the 523 who died, they will live on in the memories of those they leave behind.
Their legacy, like that of the ADF personnel who served in Afghanistan and Iraq, is both confusing and controversial.
While it is well-documented some veterans of previous conflicts viewed the Vietnam veterans with disdain, our soldiers served bravely; displaying skills and a battle readiness worthy of their predecessors.
One of the things that set them apart was that for the first time in Australia's wartime history there was an active and powerful anti-war movement. This culminated in the million strong "moratorium" marches.
Vietnam, due to a seismic shift in the social landscape and being the first "television war", never had popular support.
The hellish images screened into Australian homes every night on the 6pm news raised difficult questions such as "why are we there?", "what do we hope to achieve?", "why aren't we winning?", and "when will it end?"
Governments of the day reacted with arrogance and belligerence. When protesters laid down in front of US President Lyndon B Johnson's car during his visit to Sydney in 1967, NSW premier Robert Askin responded "run the bastards over".
The parallels with Afghanistan, the only conflict in which Australians were engaged for longer than in Vietnam, are painful and obvious.
The shockwaves sent around the world by the fall of Kabul in 2021 made it obvious neither American nor Australian leaders had learnt anything from the conflict in Indo-China. A new generation of politicians and commanders made all the same mistakes.
While it is not true, as many assert, there were no welcome home parades - 15 battalions paraded in separate official marches between 1966 and 1971 - the homecoming experience was bitter for many.
Official war historian Ashley Ekins wrote: "... small groups of soldiers were returned to Australia through wounds or illness. For them the experience of homecoming was often rapid and disorienting, with little consideration for their readjustment and no formal welcome".
What should not be forgotten is that while many Australians suffered much, this pales in comparison with the experience of the Vietnamese people.
America and its allies dropped 14 million tonnes of ordinance on the country; three to four times what was dropped on Western Europe during World War II.
More than a quarter of a million South Vietnamese soldiers were killed and 784,000 were wounded. North Vietnamese army and Viet Cong casualties totalled at least 1.1 million killed, 600,000 wounded and 300,000 missing.
Much of the country was left a cratered ruin and, as a result of a US trade embargo that did not end until 1994, the economy took decades to rebuild.
Given the world is even more volatile and dangerous now than when Menzies committed combat troops almost 60 years ago, the message is very clear: "those who cannot learn from history are doomed to repeat it".
Or, as Pete Seeger and Joe Hickerson so eloquently put it in 1960: "Oh, When will you ever learn?"
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