I don't think either the US or Israel is all that worried about "defanging" Iran's actual military. Their proxies, like Hezbollah, Assadist Syria, Ansar Allah, and Kataib Hezbollah? Sure. But they've mostly already accomplished that. I think Iran's actual military is kind of a joke in military circles?

Israel definitely wants to get rid of Irans ballistic missiles.

That said; if you believe (as do some commenters here) that Israel could ignite nationwide protests with 100,000s of people whenever they want, then they definitely don't have to worry about Irans army

I don't believe Israel can ignite nationwide protest and sort of assume, as a military/strategic matter, that Israel's primary response to Iran's MRBM capabilities is deterrent. Israel control's Iran's skies. I think the direct military part of this conflict is basically over.

I'm just a message board commenter, this is just a take.

I agree - their primary aim is to defang, but the regime change will need to follow so that they can put someone in power that they can control.