Israel should not be inhibited by world opinion.
If Israel fails to act, they will suffer the consequences of failing to act.
If Israel acts, they will have to live with themselves in the morning
Beats the alternative.
Tell the Israelis to train a bunch of snipers like Jude Law in the film "Enemy at the Gates". Give their sniper brigades publicity and make them heroes, and send out a slew of determined snipers to hide and wait for a terrorist or suicide bomber to act. Then blow them to hell.