you said iran has nuclear weapons
Soleimani and Iran knew the risks. They went to Iraq to fuck with the biggest military power in the world and almost succeeded in doing another 1979.
Baghdad airport was partly used as a US air base not so long ago (and some might argue it still is). That's the type of diplomatic immunity this motherfucker thought he had.
And yes, Iran likely has nuclear weapons. But there's a difference between having nukes and being able to deploy them in any meaningful way.
I'd say the US should be more worried about a ground invasion of Iraq. Iran was taking over Iraq using 'soft power' but they might resort to different methods now.
I don't think there will ever be a massive invasion into Iran itself. The campaign will focus on taking out the proxies such as Hizbollah (who do most of the heavy lifting for the regime anyway).
Followed by cyberattacks and taking out their leadership and somehow coming to terms with a new regime.
To escalate Iran would have to fight and defeat the US forces in the region, which outside of Iraq and Afghanistan are spread out and mostly out of their reach in US allied countries.
They don't have the resources to take on the US and its allies in the region. They can do some damage but such a move would be very unwise.
Also I expect some heads will roll at Iranian intelligence once they figure out Eric Trump gave them a 30 minute warning something was about to go down.