On the eve of his trial last year, David McBride entered a guilty plea to stealing and disclosing military secrets after court decisions undermined his defense.
McBride, a former military lawyer, claimed he had a moral obligation to speak out.
Evidence of 39 Afghans having been unjustly slain by Australian forces during the conflict was later discovered by a historic investigation.
Australia has been rocked by McBride’s case, which has drawn attention to what some see as weak protections for whistleblowers and a glacial prosecution of soldiers who are accused of killing without consequence while flying its flag.
In court, McBride, 60, acknowledged that he provided the Australian Broadcasting Corporation (ABC) with mountains of documents, claiming that he did so because he was worried about commanders’ attitudes and what he perceived to be the “over-investigation” of soldiers.