Weekend Suicide Bombings

I'm sure everyone knows what happened over the weekend in Israel: three suicide bombers detonated their bombs (and themselves) in crowded areas. 10 were killed when 2 bombs went off at a mall; 15 were killed when a man exploded on a bus in Haifa.

Obviously, it's an attack on Israel. Hamas has claimed responsibility. Hamas opposes the state of Israel and seeks its destruction. They also, therefore, oppose any peace accords with the Palestinian Authority. They will continue bombing as long as Israel exists.

In retaliation, Israel fired missles near Arafat's offices. They are also occupying some Palestinian land. One can imagine that this is only the beginning.

There is obviously a continued threat. So, my question - what is an appropriate response? I'd especially like to hear tw's opinion on this, but everyone should contribute.