Israel-Gaza: Back to Square One?

For the better part of two weeks, we've been hearing that neither Israel nor Hamas wants a prolonged fight. So why is a tenuous ceasefire in tatters? With rockets fired on Israel and army reservists recalled, is it back to square one? Both sides may be war-weary but it seems there is also little appetite for compromise between an Israel that doesn't want to loosen its blockade of Gaza... and a Hamas that doesn't want to disarm.