This started because Hamas asked for a 6 month truce, which allowed Hamas to put together enough munitions to start bombing Israel again. Israel complained to the appropriate people (read UN) to no avail and finally(!) decided to do something real about it. Israel has not only invaded the Gaza strip, they have activated an estimated 10,000 reservists in case Hezbollah or any other Arab nation-based group should choose to attack from the rear.
Hearing the UN and various Arab leaders start to whine about Israel exercising it's right to defend itself is sickening. Palestine as an entity has been attacking Israel for decades, and Hamas has spearheaded the attacks as long as it has been in existence. The UNSC is meeting to decide what they will do. The US is opposed to a UN presidential statement because it goes in to the UN's permanent record, while a press statement does not.
Riyad Mansour, the Palestinian U.N. observer, says that over 3000 Palestinians have been killed since the beginning of the air attacks, but the Gaza health officials say only 480 have been killed. Of course, Hamas has launched over 400 rockets in to Israel since the beginning of the air campaign, but there were no UN discussions about that.
And, of course, there's the standard statement from the terrorist group,
"You entered like rats," Hamas spokesman Ismail Radwan told Israeli soldiers in a statement on Hamas' Al Aqsa TV, broadcast shortly after the start of the invasion. "Your entry to Gaza won't be easy. Gaza will be a graveyard for you, God willing," he said.Uh huh. Push them in to the sea.
Edit: Dershowitz put up an essay at the WSJ: Israel's Policy Is Perfectly 'Proportionate'
h/t: No Apology