1. UN general assembly votes have no force of law.
2. Resolution 242 clearly states that part of the west bank & gaza strip should be for the palestinians but does not mention, even negates, the 1949 cease fire line (which some people mistakenly quote as the 1967 lines)
3. The 1949 ceasefire line has no ethical, legal, historical or ethnic relevance.
4. The west bank and gaza were not independent high-contracting counterparties (HCP) under international law (i.e. not sovereign), therefore the geneva convention does not apply
5. British mandate law has never been rescinded by the UN. This encouraged Jewish immigrant to settle the remains of the palestine mandate after trans-Jordan was split off and closed to Jewish land ownership (although actively thwarted on the ground by the British occupying administration).
6. The west bank and gaza were won in a defensive war, therefore under international law they now belong to Israel.
7. 90% of the non-Jewish population of Israel is decended from illegal economic migrants from the 1940s (as put beyond any doubt by the UNWRA founding charter). The fact they were prevented from re-obtaining citizenship in their countries of original does not negate their ineligibility to ownership of Jewish native land.
For example, Jerusalem was majority Jewish in 1900, is majority Jewish today, and the "so-called" east is also majority Jewish. Therefore any request to cleanse Jews from beyond the 1949 lines could be considered rascist and invokes ethnic cleansing of the natives (the Jews).
Ultimately the UN is still largely governed by rascist fascist dicatorships, so even if law was passed directly against Israel, it could be comfortably ignored by Israel, which should withdraw from the UN in any event (this benefited the Swiss economy no end).
So why did Obama suggest the 1967 lines (enthusiastically backed by Hague) ? He is too intelligent to have blundered. We all know that the 1967 lines (aka 1949 ceasefire lines) are code words for no-peace, based on the idea that prolonged conflict will bring about the end of Israel. They are also completely impossible. Ethnically cleanse Jews from their native Jerusalem and give ownership to people who migrated relatively recently from north africa and saudi arabia ?
Obama obviously believes strategically that permanent friction with Israel will raise his status in the Muslim world, for which he has an outreach program.
The only thing that could thwart his plan is some crazy left-wing government in Israel actually giving in to one of the invented "blocking demands".
This would require another blocking condition to be created (e.g. (i) Arafat agreed with Rabin he would settle on 90% of the west bank with Ramalla as the capital. Then, after Rabin's death, during camp david, as Barak had agreed to all his previous demands he had to invent a new one, the idea that the whole of Jerusalem should belong to him. (ii) The right-of-return demand came even later, and was adopted to thwart Olmert's plan to give into all previous demands)
Yitchak Shamir, we need you!