One thing I got from Rashid Khalidi’s The Hundred Year War on Palestine is that the Zionist entity is like a chaos dragon (sorry for the JBP term but it really fits well) for the entire Middle East. That role is incredibly beneficial to the US. They keep all the other MENA states from acting with a united purpose. Essentially, the Zionist entity keeps them down and their leaders dependent on the US. Every neighboring nation must devote signficant resources - financial, political, social - just to try and keep Israel from fucking up their shit all the time.

How this is done is multi-faceted. Of course there’s Israel’s decades-long history of attacking neighbors unprovoked (literally what’s happening in Syria right now). By preventing any right of return, the status of Palestinian refugees in places like Lebanon and Jordan creates tremendous social pressures which leads to social and political instability. Basically, if you are a leader (elected or otherwise) in the Middle East, you have two choices. Either side with the US/Israel (and against the Palestinian people), or don’t side with them and Israel will find reasons to bomb you or mess with you or try and get the US to view you as part of the “axis of evil” or supporting terrorists or whatever.

If the Zionist entity were to be destroyed, you would almost immediately see other MENA nations act in a more unified and confident manner - which is a very direct and real threat the US’ strategic position in the region and the flow of oil.