The UN has always been about as useless as a milk bucket under a bull!!! 
The UN does absolutely nothing lately. If it is some anti-USA resolution the Chinese and Russians are all for it, and the USA vetoes it. If it is something against N. Korea or Serbia or something China and Russia veto it. The common problem is the veto power of the permanent members, ala Russia, the USA, China. The USA has used it's veto power consistently since the 1960's in resolutions passed against Israel, and the others have used them with Serbia, Kenya, N. Korea etc.
When the Ukrainian ship MV Faina was seized last year, it was literally held for months. There was no way Ukraine could do anything militarily, and finally they ended up paying a lesser ransom to free the ship and crew. Russia did step up patrols in the region, only because 3-4 of the crew were Russian nationals.
Curiously the only time the USA has ever gotten praise for anything from N. Korea was when the US Navy assisted a N. Korean ship that had been overtaken, and they fought off the attackers and the Navy sent people over to assist the crew afterwards in securing the ship and assisting the wounded crew.