Because the Iranian leaders have been repeating constantly over the years that they will wipe Israel off the map. They are also behind the Hamas and Hezbollah attacks, and have been the world's biggest sponsor of terrorism. Who would be foolish enough to allow them to have nuclear weapons?

And look at today: Israel targets military installations and warns the people to move out before attacking, Iran targets cities and civilians.

Israel never attacked anyone unless attacked.

Gaza is a sad situation, where Hamas is responsible for everything. What Israel is doing there is unfortunately the only way to end the bloodshed that had been going on for 75 years. This was confirmed by Hamas, as they clearly repeated many times that they will continue to do what they did on October 7th, again and again and again (and Iran is 100% behind this).