What does NATO have to do with a rule/law that Ukraine comes up

If you don't understand that vassal countries do whatever their masters tell them to do then I strongly recommend reading the european report on the vassalisation of europe. https://ecfr.eu/publication/the-art-of-vassalisation-how-russias-war-on-ukraine-has-transformed-transatlantic-relations/

This isn't specifically about Ukraine, it's about how the war in Ukraine has vassalised the EU countries, and how things like Brexit led to pressures that forced the EU into obeying America, but it's a useful primer for you to learn about how other countries become subservient to american interests. Particularly because it's a report funded and produced by the EU and other nations.