[pc86]

If "I want this land" is a legitimate reason to initiate a war then basically anything is a legitimate reason.

[iso1631]

I can see the reasons even if I don't think they're legitimate. I can see the reasons why someone steals from someone else, or rapes or kills. Those reasons aren't good enough, but most people have reasons to do something.

Why is America attacking Iran? What's the official reason? What's the actual reason? Does anybody know?

[tliltocatl]

You are confusing reason as in "why they did it" vs "why they ought to do it".