> You definitely can kill 2.1 million people by bombing them. It's actually way easier than doing it with a gun

Only if you have enough bombs, which they need to constantly purchase from the US using aid money given to them by the US.

They don't have the stockpiles to eradicate without using their (not so) secret nukes. If they were to do that, there'd be a lot worse follow on effects for Israel. If they simply trickle the deaths over time, people get tired of the horror and need to look away for their own sanity.