Its a matter of survival.
The UN is as useles as Teats on a boar hog.
Europe is anti-semite
The US is busy in Iraq . More interested right now in their peace plan that wont work with the Palestinians and supporting the Palestinians with millions in aid.
I believe even the Arabs are silently hoping Israel will stop Iran, since no one else will.
Yes I believe Israel will have to make that call themselves.
Israel survival in the war on terrorism depends on a strong stand against all terrorist acts.