Hamas last waged a campaign in 2008-2009. If there was a method to cleanup Hamas, Israel would have done so by now and Gaza would be having a milder ruler like in West Bank. All attempts to rid Gaza of Hamas have failed over last 15 years. So, this war is not new, it is just a Groundhog Day in Gaza.
en.wikipedia.org
In fact, part of the tragic error Israelis made was, they thought since more and more Gazans are now working in Israel, Hamas would like the money flowing in and will moderate its ways and become more Fatah like.