Lebanon and Iran and Qatar and Yemen and Iraq and Afghanistan and Turkey and Egypt and maybe even Russia would obliterate them.
I have serious doubts as to the ability of some of these countries to be able to match up to Israel militarily, even aside from having other things to worry about at the moment - Russia in particular does not have the privilege of fighting two wars right now.
There’s also the fact that Israel is a nuclear power - they almost used their nukes in the Yom Kippur war, which is what prompted the US to actually start resupplying them. If an Arab coalition were to attack Israel now (especially with Netanyahu in power), there is zero chance that they wouldn’t actually do it this time, and everyone knows this. No one in their right mind would try and pressure Israel to that extent, and most foreign powers would be highly motivated to do whatever it took to make sure that didn’t happen.
Finally, if the US were to leave Israel alone, China would probably step right in to fill that void, and would be well-suited for it too, given that they have relatively good relations with most of the Arab nations (IIRC). So not only would the US lose a massive channel of influence in the region, they’d be allowing their largest geopolitical rival to consolidate their influence in the region as well - wouldn’t Biden be absolutely raked over the coals for that?