I honestly believe that here is the lodestar of the body of teachings generally called Catholic Social Thought. I believe also that here is perhaps the Pope's timeliest intervention on the world-historical stage. None may ever legitimately attack a single innocent. The Holy Father is saying that these norms are the indispensable core of the common good. They are the backbone of any decent and just social order, for they alone can anchor inalienable human rights.
History seems to have settled that controversy as much as moral insight settled it.
This trajectory has lacked what might be called a distinctly Christian starting point. The Pope does not suppose that by his so saying, the world will change. But the question is secondary.