After losing one of the longest-running defamation cases in Australia, former soldier Ben Roberts-Smith is back in court trying to overturn the original decision. The Victoria Cross recipient had his case against the Sydney Morning Herald/The Age/The Canberra Times dismissed back in June after Justice Anthony Besanko found the publisher had proved he was a war criminal. Roberts-Smith’s lawyers are arguing the judge made a legal error in finding him involved in the murder of 4 unarmed prisoners in Afghanistan. Yesterday, Bret Walker SC told the hearing the difference between lawful and unlawful killings in war was “at the heart” of the case. The original defamation hearing lasted 110 days and cost $25 million in legal fees. This case before the full bench of the Federal Court is expected to last 10 days – with some parts involving national security heard behind closed doors.