Surely you can steel man this yourself. Iran wants nukes. Iran has stated it would like to destroy the US and Israel. Israel is an outpost of Western democracy and our ally. Iran has missiles that can reach Europe. Iran is an ally of Russia and China. Iran wants to control the passageway for a big chunk of the world's oil. Cooperation between Israel and its neighbors would be a great asset to the world economy.
This is not comprehensive and maybe you can quibble with some of it, but it is not mysterious why we might care.
This is not comprehensive and maybe you can quibble with some of it, but it is not mysterious why we might care.