I'm not sure about the energy situation but that aside Israel needs the US far more than the US needs Israel. This is because the US provides the diplomatic support necessary for Israel to continue its illegal colonisation project. Also because the US gives Israel billions of dollars in 'aid' every year, money which pays for the illegal occupation. And the US destroys any countries that Israel wants destroyed. I don't see any way the US benefits from the relationship. On the contrary, it loses massively and about 5 trillion dollars of US debt is down to wars fought for Israel, principally Iraq, not to mention the thousands of dead American soldiers.