If you're still a little confused as to why this current fighting is going on this is a fantastic, albeit long, article
on why that I recommend everyone read:
For Hamas, the choice wasnít so much between peace and war as between slow strangulation and a war that had a chance, however slim, of loosening the squeeze. It sees itself in a battle for its survival. Its future in Gaza hangs on the outcome. Like Israel, itís been careful to set rather limited aims, goals to which much of the international community is sympathetic. The primary objective is that Israel honour three past agreements: the Shalit prisoner exchange, including the release of the re-arrested prisoners; the November 2012 ceasefire, which calls for an end to Gazaís closure; and the April 2014 reconciliation agreement, which would allow the Palestinian government to pay salaries in Gaza, staff its borders, receive much needed construction materials and open the pedestrian crossing with Egypt.