Personally, here's my take:
We can't abandon Israel, seeing as it would lead to genocide and the driving of any Jews living there into the sea - which is clearly bad. But the biggest problem is that the Israeli lobby in Washington (stemming from their right wing party, Likud) needs to be kicked out of Washington, and America - being far stronger - needs to take the upper hand.
We need to let them know - stop the atrocities perpetuated by the IDF against innocent Palestinians in the West Bank, or face us leaving. They wouldn't risk that, we need to use what power we have to be in the position of power here, not the other way around.
Other than that, we need to work fervently with the Israeli and Palestinian peace movements to do whatever we can to come to some kind of conclusion.
Israel has the most powerful military in the Middle East (except possibly Turkey) and has nuclear weapons, so the argument about abandoning Israel is frankly ridiculous.
