In the 1920s the soldiers left the lines of WW I France and equipped with what we now call PTS were posted to Eire. The
PR chaps would have their work cut out to try and justify some of the treatment then handed out to the Irish people. The bottom line is that it is unatural to expect an individual subjected to war to return home armed with a pipe and slippers, happy to watch TV and read the paper. Especially when the 21st Century war is often nearer to trench warfare than any conflict in the latter part of the 20th Century.
I think that if you add to these stats the UK homeless who are ex-servicemen unable to readapt to society you may start to get to the truth of the matter.
Any conflict is indicative of mankind having failed. Those whose lives are changed forever need care; and a prison and street corner is not a place of care.