That's not a distinction which works across history iconoclastic. Terrorism typically has an aim, a goal, and the targets are chosen in order to progress that goal. War typically has an aim, a goal, and the targets are chosen in order to progress that goal. Sometimes that includes killing civilians deliberately. Sometimes that doesn't. The definition of terrorism is the use of terror/fear in order to progress a political aim. It's not a tool of just jihadis cutting people's heads off or flying planes into buildings. Fear as a tool for repression and control has a much longer history than that. And one which very much includes the time period when the new testament was being written.
The concept of a 'crime against humanity' dates from when iconoclastic? Even the Lex Innocentium is late C7th AD, and that in no way is representative of any point of history before or since. Warfare is brutal and uncivilised, much as we sanitise or mythologise how we treat it.