In the long-run UN action may freeze the negotiations into a discussion of a two-state solution, but UN action is not required to reach this eventuality. Even Avigdor Lieberman on the Far Right accepts that there will be two states, and that has been the basic premise of the Peace Process since 1994.  On the issues which have actually prevented a two state solution from coming to fruition- disputes about borders, armaments, security, and settlements, the UN would accomplish nothing. Furthermore, it might well make both sides intransigent, the Israelis due to perceiving themselves as being backed into a corner internationally, the Palestinians due to the belief they no longer need to make concessions.