I served almost 11 years in the US Army. End of the '60’d till the late '70’s. During that period there were ‘gays’ in service. At that time most tended to be in the medical service MOS’s(Military Occupational Specialties - your job).
Why? I haven’t a clue. I was not in that area so I don’t know how or if it affect unit operation. I think, and its just my opinion, that any problem, or lack of problem, was based more on the individual and their personality rather than any bias or anti-‘gay’ feelings of the fellow workers. Yeah, there were undoubtedly backward asshats who were just plain prejudiced against homosexuals, and these people also probably expressed these prejudices in blatant acts. But I’m pretty certain that they had some other personality defects - drunkenness for example -that made them intolerable in most other areas of their life.
In my time I traveled quite a bit and saw many different bases and did notice a something of interest.
IMO lesbianism is/was more prevalent than male homosexuality. At just about every fort there was at least one barracks building that was pretty much known as the “Womens/Wymins” barracks. It was the preferred base housing for women who liked women. I never noticed this same feature for ‘gay’ men on any base. I chalk it up to it being easier to overlook the women than the men. Heck, butches and dykes wearing mens uniforms and having short hair just isn’t going to stand out like a flamer. Maybe that was the case, maybe not.
I came across a few ‘gays’ in the combat units I worked with. They were all professionals and kept their preferences quiet.
Another thing, every services has ‘gays.’ Even the Marines. In the San Diego area there are ‘gay’ nightclubs around Camp Pendleton. Popular with the some of the troops. And there is at least 2 ‘gay’ clubs that are favorites with ‘gay’ Marine aviators; who are officers. Some career men.
IMO - Yes, homosexuals, of either gender, can, and do, make good Soldiers, Sailors, Airmen and Marines.
Does their presence affect/effect unit cohesiveness and mission accomplishment? Possibly. But if this were the case this would be dealt with and removed as a problem factor. That is - it would not happen on a regular re-occurring basis. Just my opinion based on my experience.
Oh, and ‘gay’ persons can be life-takers and heart-breakers just as effectively as heteros.
I hope this answered some of your Q’s. Just my opinions.