I think my father needed his sleep. I think that was his main goal: Getting enough sleep so he could function. There likely were other benefits. As another com

I think my father needed his sleep. I think that was his main goal: Getting enough sleep so he could function. There likely were other benefits. As another comment here notes, alcohol is also a blood thinner. My father was on blood thinners for many years after being diagnosed with a heart condition and did have a large clot at one point that he could have lost his leg over. But I think the fact that he apparently began winding down his drinking when he left the military means his primary reason for drinking was likely to manage his fear of being sent back to the front lines. That's not the same thing as avoiding bad feelings per se. It's more like moving stage fright out of your way because your paycheck depends on your performance and you need to perform in the here and now regardless of how you feel.