Yes, those lessons as well, but mainly that as long as we support Israel, radical Muslims will continue to try and do harm to US citizens in any way they can. The only way to prevent that from happening is constant surveillance of terrorist cells in these 3rd world countries. Drones have become a safe, economical way of doing that, like it or not.
You can debate whether or not drone strikes are ethical or not, but just remember this. If they had the same tools as us, they'd strap a nuclear warhead on them and blow up New York city and Tel Aviv without blinking an eye.