This time you’re conflating allowing an entity into a group with endorsing a specific characteristic of that entity.
It kind of is. Would they have allowed a communist nation to join? I highly doubt it. They could’ve easily said, ”no, you’re fascists, go away.” It’s not like getting fucking Portugal to join was essential.
Also you’re still keeping the whole “if they did so half a century ago, they approve of that kind of thing now” angle.
Hungary and Poland are fascist.
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.
I would agree with this, because at face value it’s true. Liberals are always calling NATO a group of civilized, European, democratic nations though, so you can’t have it both ways.