re: If the US did not exist
Israel would be no threat to its neighbours (it may even not have existed to become a threat to its neighbours ir if it did exit (after all, France was much more pro-Israel until 67 than the US was), it's borders would have rermained those of 67. We see that occupying territories has in no way made Israel safer.
The Arab world would not have a common enemy and they would fight against each other instead of against those who don't interfere with their business.
It's a matter of action triggering reaction.
If we don't bother them, they don't bother us. If they don't bother us, we don't bother them.
Sure, dictatorships will still exist (but they do inspite of the existence of the US anyway).
Raoul