In my (very limited) experience of wearing a uniform (inactive reserve duty and in school only), the people who treat the wearers of military uniforms the best are those who once wore such uniforms.

I don't live in an area with many who wear a uniform, but when I know someone is, is going to or has recently been in uniform and in eating or drinking where I am, it's on me. It happens rarely but has aleays been a very pleasant experience. Do it once, and you'll want to do it again.