As Immortal Technique said in a recent interview, the US can't really protect Israel, or anyone in the region. It can only attack and deliver weapons, but it has no (credible) diplomatic voice with which to pursue anything but more war. The US cannot tell anyone "hey guys, you need to stop" and even get a hearing. That's not just because "they" all hate the US 24/7, unchanged, regardless of what is done except killing everybody, that's in part a result of how the US tends to interact with the region and the conflict(s).