Israel is absolutely not the boss. The US only started caring about Israel after the 1967 Arab-Israeli war, when they clearly demonstrated they could effectively suppress their Arab neighbours with military might. It is the same as supporting the most powerful warlord in any other state (Saddam Hussein, Gaddafi, the Shah of Iran, countless others), but projected over an entire region that also happens to contain Saudi Arabia.
This is also why the US has been funneling israel billions of dollars in aid to develop its military industry over the past few decades. US has gained plenty from this alliance, it has projected power in the Middle East through an ally that is terrifyingly overprepared for war, allowing it to maintain the artificial order in the Middle East and petrodollar dominance.