The world has never been bound to defend Israel - as a matter of fact, Muslim-dominated nations and peoples have been trying to kill it for 66 years, and another part of the world that is obliged to kiss Muslim ass, in order to obtain access to oil resources, has been enabling them all along.
Instead of Vetoing various UNSC measures over the next two years, the US will, in all likelihood, merely Abstain during some of those votes against Israel.
Until January 20, 2017, anyway.
The Israelis know that they merely need ride-out that interim, while our Lame Duck attempts to do more damage to the relationship, until things get better again.
A matter for some degree of concern, as an interim measure, but certainly not the end of the world.