I think you need to lookup the definition of the word hypothetical. The point of the exercise is to imagine a scenario where the players are reversed to imagine how they would react.

My quibble is not the hypothetical, it is your implicit claim that the situations are similar. Thats what an analogy is.

The mere fact of your defending Russian invasion of Ukraine is enough to completely discredit your opinion on the matter.

>NATO is a defense pact.

Oh lordy. I only ever hear this on the internet and I always find it bizarre. Who is telling people this? University professors? Where and in what subjects? Prime time news programs? Again, in what countries? I've been in the military for 20 years and I've never heard an NCO or officer utter these words. Because it's nonsense. Defense pacts don't conduct totally-offensive air campaigns against countries that none of their members are at war with.[1] There is no formal legal mechanism for NATO as an organization to act as an enforcement arm for UN Resolutions, by the way. If there was, NATO probably should have been bombing Israel since UN Resolution 497 in 1981.

[1] https://www.nato.int/cps/ic/natohq/topics_71652.htm