I think "just" would be more correct than "justified", which is what the ge- prefix in the German word adds, I believe. "rechtfertig" would be correct, though, which I think doesn't translate to justified.
Do correct me if I'm wrong though. I'm not a native German speaker.
I am merely transposing the same words we have for them in Dutch to German. i.e. rechtvaardig and gerechtvaardigd
Righteous was my first thought too. Fair just and righteous are all acceptable translations, as far as I understand. Yet, in contemporary use, "righteous" is more commonly preferred when expressing a person's characteristics: "She is a righteous woman"; whereas "just" and "fair" are more commonly used with actions when the people taking them are not the focus. Historically, righteous had a broader range of use but it is limited today, with a hint of negative connotation implying being judgmental.