As I understand it Netanyahu had two reasons to eliminate Hamas = security threat and poor polling.
If Biden breaks ranks, he will galvanise the holdout Israeli factions to get behind Netanyahu for the country's survival. The knock on effect is the damage to the USA economy from punitive payback.
The Israel system has a security council which can pull the rug out from under Netanyahu if things go pear shaped. The country itself has a nuclear deterent if the neighbours get ahead of themselves.
