It is not that simple, it's not black and white, how many years in history do you want to go back to find the causes... so don't pretend it is.
Hamas are a bunch of fundamentalist murderous thugs out to erase Israel from this world and raise a theocratic state that the Palestinians only will suffer in. Netanyahu is a corrupt crook that needs the right wing fringe lunatics to stay in power with 52 or so percent.... the settler and apartheid policy has created that monster...