the trauma of war is still not understood

I well remember a job hunting video where a guy was asked about his experience in the Falklands war. His reaction was to end the filming session abruptly without explanation. The "job seeking" trainer dismissed him as purile. I tried in vein to highlight some supposed bad experience causing his reticence. To no avail. And this was a personnel officer. She didn't understand, PTSD, survivor guilt, shell shock and a dozen other kind phrases or I would have used them. I declined to be considered for employment with her company later!

The effect on unwilling conscripts of actually killing someone (gore & all) was well understood in WW1, it was just not tolerated. Hence the white feathers.