Average soldier's age in war is about 18, just after school. Impressionable. Examples set by more senior ones. There is only so much you can do when not actually busy in operations. Then in a base with minimum facilities. It changes your life forever.

Previous wars' hardships were clear in the veterans' attitude and actions in peace time, although not understood then. It gets better as time goes on but never goes away. Treatment helps if you are willing to undergo it.

The South African Army had an excellent destressing programme in our long term low intensity bush war, that those who managed to sidestep or escape, still to this day regret not going through.