It isn't so simple as "both to blame". This incredibly lopsided "conflict" is fuelled entirely from outside. Smuggled rocket parts keep Hamas going and three billion a year military aid (unconditional, of course) from the US makes Israel feel immune. Naturally, Israel gets great comfort and encouragement from us in the west who hardly ever dare criticise even their worst outrages in Gaza, whilst simultaneously condemning in far stronger terms those satanic yet ramshackle rockets that nearly always miss. Apportioning blame is (apart from being useless in terms of making progress) impossible without including outside influences in the reckoning. The balance of such influences between the two sides is reflective of the disproportionality of Israel's response to its irritating neighbour. None of this is intended to let anyone off the hook, by the way.