How can the UNO bring in accountability of all the wrong actions taken by nations around the world?

How can the UNO bring in responsibility and accountability on all the wrong actions and works done by the wrong elements of a nation,as the problem does not remain with in the borders of that nations but spills out to other nations around and far off thus bringing in unrest to world which is stuggling to solve its previous problems and have not yet seen light to their problems.|||The UN cannot even handle accountability for its own actions and its own staff and officials. Errant nonsense to think that they can hold someone else accountable for their actions when they can't even manage to do that in-house.