UN resolution because India says Pakistan has to vacate Azad Kashmir first to hold the demanded plebiscite.
But what they dont realize is that even for planning to vacate Azad Kashmir for holding a plebiscite, they need to sit on table with Pakistan. It's no child's play. Vacating Azad Kashmir & not getting the promise of plebiscite for Kashmiri's will have consequences that need to be told at such a meeting with a third party/guarantor present such as UN representatives themselves.
It won't come to war really when China is involved. The hardest problem is convincing Indians to send their troops without any resistance from Pakistan and China to territories it says belongs to India and for holding a plebiscite in all six of these valleys. India is simply unprepared (unwilling) for that despite tall claims of dominion over these territories.
BUT
If it fails to conduct plebiscite or refuses to vacate the valleys (which it will) a war should ensue. America and Israel will not help India, don't worry (because Indian war planners will disappoint them both in a very short time).
The resolutions practically mean nothing anymore, and China will never get involved militarily.