so what is the difference?The difference is that some people use the UN as a moralist figleaf to do exactly what they do or don't want to do. Combined with an absolute veto for those who need it least and an increasing number of nations who regard defiance of the UN as a moral action, it cannot hope to succeed.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1