Two problems of political philosophy.

On the first question, since people are concerned, there are two kinds of people involved here. One is to make plans to destroy the people of other countries, and the other is to destroy the people of all countries by other countries. When you talk about this law, there are two people involved, but you say that only one person gives the law legitimacy. There is a contradiction here, so the law only agrees with its part of "human" law, not another part of "human" law, unless they also agree with it.

On the second question, I think it is meaningless to talk about legality. Because authority comes from strength, and the rights generated by strength are completely meaningless even if you have doubts. Although giants of one kind or another have painstakingly demonstrated the rationality of the existence of some form of state, those are somewhat self-deceiving. The so-called country and its authority, relying solely on strength, may be consistent with "legitimacy" at a certain stage, but there is no guarantee, because whether "legitimacy" itself is legal or not and whose laws apply are all a bunch of questions, and "legitimacy" itself remains to be discussed. So far, which country really relies on "people's judgment" rather than strength? The question of authority has nothing to do with the question of legitimacy, but it may also be to cover it up and decorate it a little. Just like the relationship between the likes and dislikes of diaosi and the behavior of the government. They just need strength, and some people will defend the legitimacy of this strength. But in essence, they are still two unrelated things.