Lets say you have a wife, and 5 kids. Terrorists break into your house and rape your wife and murder 2 of your kids.
There are 2 options presented to you.
1. you can call the military and they will bomb and kill the terrorists but 20 civilians will die.
2. a special team of negotiators and police spend 3 months slowly working with the community to try and get them to give up the terrorists. 80% of the terrorists are caught. 5 police officers die. The rest are free. In the mean time they kill your wife and cripple one of your remaining kids.
Which one do you choose?
All the anti Israel people want Israel to pick option 2, when Israel's responsibility has to be to protect its own.
Also there really is no such thing as international law. There is only what America allows and does not allow. It may not be fair but thats reality. Those really are the facts on the ground.