They in fact do not, the variability in how much genocide they should do and how racist they should be as well as greed for power is enough to create conflict. Not to mention the racism that exists within zionism itself as it's white supremacy that has had to bolster its numbers with "lesser" races. The only thing holding it together is our tax dollars and military support.

Edit: once the outlet of expansion stops they will eat each other like fascists and colonists are prone to do.