“Sometimes, there was an overreaction to what didn’t need an external inquiry to be looked into,” he said, referring to his experience in war. “It was something that should have been handled in theater.”

Aside from fostering protectionism and cover-ups, he said, emphasis on civilian deaths may unwittingly give the enemy a tool.

“Your opposition also know that accusations of civilian casualties are a lethal weapon in the social media space,” Mr. Shanahan said.

Finally there are the logistical challenges of an investigation, he said. “There’s a lag time in the time between an incident happens and the inquiry happening, and the war goes on,” Mr. Shanahan said.

“There’s no way you could guarantee that nobody has spoken to each other,” he said, warning that either the accusers or the accused could potentially fabricate false narratives.

2. Follow the broader inquiry through.

The inspector general’s investigation will prove invaluable because it is looking beyond an individual case, said Bob Lowry, who served in the Australian Army for 30 years and is president of the Australian Institute of International Affairs in Canberra.

“When it’s happened twice, three, four times, you’ve then got a systemic problem,” he said. “Was it someone from above demanding measures be taken? Was it something that grew from below? The thing to do is to talk to all the people involved, and find out what it is, where it came from, and what caused it to be in the first place.”