Fighting in WW2 from the invasion of Poland to the 2nd-to-last month of the war, including being wounded, was probably psychologically damaging in the extreme. It’s easy to imagine that sacrificing so much for so long to the losing side would lead to an inability to cope with certain historical events, along with the alcoholism.
I’ll pencil in feeling empathy for a dead Nazi war criminal’s PTSD somewhere in 2050, when all the carbon emissions will probably have killed me anyway, if old age hasn’t.