PTSD

[Mitra]

who fled during, or after, what appears to be a defeat

Flee in battle and desert are very different; if the battle was a defeat all the soldiers (or a good number of them) survived are theorically fled in order to survive, and if it was a victory they should flee for panic toward a protection point first at all, in 180° respect the enemy; normally they are seen by the officers in rear. If they was condamned to death for fled, is strange anyway the use a word like that, more adapted to describe a diarrhea attack

Desert is a conscious act normally made when not surveyed (or think not be seen) at example in march column, during the night, etc..