Israel, with its heavy-handedness that is apparent each and every time, tries to smack Hamas out of Gaza and out of the equation; a very 'original' and 'great' solution (they tried that last time in 2008...or 2009?) which can be greater if not for the fact that Hamas has been really dedicated towards serving the Gazans, and thus enjoys considerable support from Gazans especially, not to mention their allies who can be found all around the world, in the form of al-Ikhwan. Israel, as usual, mentions that Hamas is a terrorist group (this is an ambiguous term at most-but I don't argue that Hamas can be really murderous, racist, extreme and bigoted sometimes in their actions and rhetoric) that fires rockets at Israeli cities non-stop since 2001 (so effing long ago, and as it happens nearly all the time, it's not even newsworthy) , and that according to them, justifies the bombing of Gaza.
Hamas, of course, mentions the Israeli siege on Gaza (I did one post about Mavi Marmara, you can find it yourself; my political position has changed a lot since then) that has been really suppressing the Gaza people's way of life; no mobility, no supplies, no money for the last I-don't remember-anymore-how-long-it-has-been few years. And that justifies firing rockets as a sign of protest and resistance against the bloody siege in particular, and the Israeli occupation in general. Yeah, that's how Hamas sees it; "We didn't start it, it has been Israel's fault all this time, for Allah's sake, are you blind?"
Meanwhile, being the slow, ineffective peace-broker as they usually are
And hence the bombing should continue for a few more days. That's the routine, that's the ritual. More casualties, more hatred, a harder way to peace.
(Update; as of now (11/21/2012, 1.49 am Japan Time), there seems to be an agreement on ceasefire between both sides)