[Karrot_Kream]

It would end up in a proxy war, surely. Iran would back Hamas and a coalition of KSA, UAE, Egypt, and Israel would spearhead the Gaza situation from the other side. It's still a shitty outcome but IMO a better one. For one, regional actors are incentivized to deal with the situation in a way that spillover doesn't affect them (Lebanon and Egypt have both been vocal about not accepting refugees), but most importantly it wouldn't be as affected by the US political news cycle and the heart-rending imperialism that creates (essentially American domestic interests and politics affecting regional politics in the Middle East, meaning Palestinians have no say over their own politics in any meaningful way, unlike American college students.) The biggest risk would probably be Russian and Chinese interests coming into the region which would surely prompt a US reaction, but I'm not sure how much Russia or China would have to gain here if the US were not involved.

It would have probably ended in a civil war type situation but at least you wouldn't have widespread famine or the bombing of hospitals or further civilian atrocities. Also forcing regional states to allocate their own resources to the conflict means there's a direct incentive to wind it down since their resources are a lot smaller than the resources of the US. Israel would eventually face domestic pushback over wartime spending and the autocratic states in the region would have to balance their funding of the proxy conflict against their own ambitions and budgets. Iran is somewhat democratic and they too could only fund Hamas so far before looking after their own affairs. A civil war would also create a generation fatigued by conflict and more open to compromise. The unilateral nature of this conflict will guarantee that Palestinians and dissidents in the region will hold this as a grudge over Israel and the US for decades and might even open the possibility of further terrorism against the US.

The US's own nation building efforts in the Middle East after 9/11 flagged due to outrageous spending that materialized in minimal results. The same effect with poorer governments would naturally circumscribe the conflict in the area.