It was Australia's longest war, and also our most secretive.

In Afghanistan, Australia's special forces were pushed to the limit of their physical and mental capabilities as brutal engagements killed 20 Australians and more than 10,000 Afghans. Also pushed were the limits of Australian and international law, as Australia's operators fought against- and with- brutal tribal warlords and narco-barons.

Increasingly enmeshed in a US-led targeting program that attempted to kill its way out of the war, the Australian SASR became one of the most feared and lethal force elements in the country. But with the Afghan government corrupt at every level, ancient enmity washing into each Afghan valley and Canberra and Washington uninterested or bereft of strategy, these killings became their own end, not a means.

In the craggy mountains, green belts and digital battlefields of Afghanistan, concepts of heroism and malevolence started to warp, and from them also emerged Australia's most decorated, visible and controversial soldier in a century.