The crucial difference here should be between those who think that violence in this conflict is justified,

Some would say that violence is never justified.
I believe it is not justified by hate or revenge.
I think that the rocketing of towns, and suicide bombing of buses full of people going to school and work, are motivated by hate and revenge.

I believe that violence can be justified in self defence.
I believe a degree of violence is acceptable to prevent or reduce such attacks ,though not indiscriminate violence.
You can argue that Israel's action have been disproportionate, and we could debate that.