This time you’re conflating allowing an entity into a group with endorsing a specific characteristic of that entity.
Also you’re still keeping the whole “if they did so half a century ago, they approve of that kind of thing now” angle. That’s an “all present day Germans are Nazis” worldview.
It’s basically the guilt by association falacy but with “like” rather than “is”, i.e. NATO likes Feminist, Machist, pro-Nazi, anti-Nazi, Flat, Mountainous and so on countries because it let countries with such characteristic in.
The only situation were that wouldn’t be a falacy is if it was an organisation explicitly about that characteristic - i.e. an Association Of Democratic Nations - which let in a country with opposite characteristics, which is not the case here since NATO is a military alliance.