Wars leave many having PTSD to some degree or other. Then, for JWs to come to the door, stating God is bringing in a New World very "soon" with no more wars, for some that is a strong 'hook.'
My dad had been in WWII at 19 yrs old and was a POW, under the Nazis. His plane was shot down, but crew landed safely in France, but then under Nazi control. He got very ill in the camp with strep, no antibiotics, and went down to about 100 lbs. Fortunately, U.S. got there. But I do think he had PTSD, which put him in a vulnerable spot to listen to JW message in 1953. It seemed in California during that time, many were Vets.
He was of the most adamant of JWs and raised us 5 kids in it to the letter. We all left JWs by mid 80s. He was disfellowshipped for apostasy.