Israel has abused their neighbors for too long, and kicked friendly civilians out of their homes, just so they can expand (illegally, too) into Palestinian territory defined by the U.N.
Since they have gone against many laws that have been set in place to keep peace between Israel and it's neighbors, the U.S. should cut a large amount, if not all funding to Israel, until they give Palestinian land back and abide by the laws that have been set.