As the author notes at the beginning, however:
Fact-checking the Israeli-Palestinian conflict is a bit of a fool’s errand. The two sides have their own narratives, which are virtually impossible to reconcile. Meanwhile, supporters of Israel in the United States — and even Israelis — have also split into seemingly irreconcilable camps, with their own sets of facts and assumptions about the root causes of the conflict.
Sadly, this is true. So true that one cannot even begin an article without readers lining up their various sides. But this piece offers some good supplemnetary details on why the UN Resolution last week and Kerry's speech are, in fact, departures from U.S. policy and even previous UN resolutions. Notably, the resolution for the first time locks in the 1949 "greenline" as an immutable boarder -- and the article explans why this is problematic from the Israeli perspecitve.
More importantly, the article tracks Kerry's source material. This is not to dispute its accuracy, but as part of the above statement of highlighting that lots of people have different interpretations on core facts. Nor are they wrong. For a start, International Law is hardly the crystal clear creature that it is often portrayed to be. Heck, even domestic statutory law, which is much more straightforward, is often subject to differeing interpretations and where interpretation of the same facts as violating a regulation or being permissible is often hotly contested.
Reading the article won't answer these questions or resolve strongly held opinions, but it may provide the interested observer with a better understanding of what people are arguing about.