https://www.bu.edu/history/files/2015/04/Khalaji-Apocalyptic...
Mutual destruction makes sense when you're a death cult and the enemy is evil. Iran nuking Israel knowing full well they will get nuked back IS rational if your belief is that Allah will reward you for it in the afterlife and they do sincerly believe that.
You should read books published by reformed Islamists. Radical by Maajid Nawaz is a good one.
They profess to believe (and they are sincere) that they will be rewarded for dying killing Israelis. There's a reason that if I tell you a story about a suicide bomber blowing up a public square in political protest you do not have to wonder what religion they are. It's not because all Muslims are insane, they aren't, it's because some of them have beliefs that make that action rational.
(For example, see how Hamas will not surrender even when offered free passage out of Gaza. They'd rather Israel grind their way through the Palestinian population bomb by bomb because they think every Palestinian killed goes to heaven. If they were rational as we understand the world, they'd realize their plight is hopeless and the only thing they ensure by staying is civillian deaths.)