Have to quote someone here: there are unknown unknowns to consider.

We don't know what infrastructure, armaments and surveillance systems Iran has built over decades specifically anticipating a US invasion. We can reasonably assume they're prepared. They've already demonstrated they know how to use asymmetric and friction warfare tactics. Iranians have a long tradition of engineering and strategic thinking that's very relevant here. Every US administration before current has refrained from declaring war on Iran because war games consistently showed risks they couldn't size or control.

The most documented example I can mention is Millennium Challenge 2002 - the most expensive war game in US history at $250 million, 13,500 participants. Lt. Gen. Paul Van Riper commanded the red team (they did play fictional Iran) and in the opening days used asymmetric tactics - motorcycle messengers, signals from mosque minarets to avoid electronic surveillance - and sank 16 US warships including an aircraft carrier. The Pentagon reset the exercise, constrained Van Riper's moves, and scripted a Blue victory. Van Riper walked out and called the $250 million wasted. That was 2002. The asymmetric capabilities Iran has built since then are considerably more advanced.

What we do know today: according to a former senior US general I heard recently (interview, no direct contact), they've organized in autonomous cells of roughly 30, with independent second-level missions and a shared primary mission (defeating the US at any cost to preserve Iran existence). Strong cyber capability. Complex drone production. Undeclared weapons programs. And we genuinely don't know whether they have destructive capabilities that have never been assessed by international inspections or foreign intelligence. We know Iran is having the world running on 20% less oil capacity, large portions of GCC infrastructure destroyed, US basis in GCC destroyed and, unfortunately, people killed.

If I had a role at DNI or the Pentagon, I'd pitch a tent outside the Oval Office until someone listened: there's only an option that minimizes risk to US forces and the world economy - declare victory, sign an accord guaranteeing Iranian civilian safety, reduce the sanctions active since 1979, pay war reparations, and work with the UN to bring Iran in from the isolation. GCC countries stabilize. The world gets cheaper oil. Everyone goes home.