I knew a coworker who claimed he was circumcised at age 18 after he enlisted in the Army. Supposedly all infantry during WWII had to be since they didn't know when the next bath or shower was going to take place once in combat. Don't know if this is still the case.
My dad fought in WW2 and he surely wasn’t circumcised. I don’t think that really came into vogue until after the war.