MAD is a well established doctrine for deterrence. The people running Iran are running Iran, not the world. The people running Israel however have undue influence on my and many other countries.

MAD only works if both parties are not suicidal. Hamas frequently demonstrates its inclination in that regard and the Iranian theocracy is similarly unlikely to be sufficiently deterred by fear of its own demise.

All humans have a will to live, Hamas is fighting against occupation not to commit suicide. The Israeli theocracy however seems to have lost control of all logic and instead is operating in the death throws of an apartheid state coming to its end. The world would be safer with more opposition to Israel.