My studies have taught me that there is only one ethic of justice: mutual respect (of a basic kind: taking one another into account). It applies to every aspect of life, including how our actions regarding the environment affect other people--even to relations among nations.

A requirement of mutual respect can be arrived at from religion, from ideology ["Equality Is All We Need" here in Medium], or from observation within material existence ["Real Justice (summarized for a '5 min read')" here in Medium]. Mutual respect is mutual respect, with the same implications for human relations from whatever perspective it might be approached.