Soldiers are also meant to be psychologically strong and that should be helpful resisting addiction, with the limited free time and much concentration, it will be difficult for any military personnel to catch gambling addiction.
That is true. Soldiers have the most discipline. They are used to following orders and just doing things even if it is hard. The amount of training they do to stay physically fit for sure contributes to being mentally fit as well. The only soldiers I know that end up in a bad place are those who are out of service already and have suffered from really traumatic events that messed them up so they use other vices to survive like alcohol or even gambling.