In one of the sub-comments, there's mention of it being used when "the army of the consul Appius Claudius refused to fight the Volscians."

While it's open rebellion, that's not at all the same as them attacking Rome. To me, it sounds more in line with Muhammad Ali refusing to fight the Vietnam war.

Well, tbh, the current US military UCMJ has the death penalty for disobeying a superior's commands or desertion when in times of war. So even now desertion is a serious crime when in combat. Muhammad Ali refusing to fight when drafted is quite a bit different than refusing to fight when you're in a military unit and being asked to directly engage enemy troops.

Yeah especially when desertion in time of crisis is infectious. Tons of generals across the ages try hard to at least prevent the majority to do the same. Armies lost when they lost morale and fled, or in other words when they mass desert.

I was under the impression that cowardice in battle was sufficient.

Decimation was very very rare as far as we can tell. It was the kind of thing that would happen like, once every century or more.

https://www.reddit.com/r/AskHistorians/comments/4v1ftx/how_w...