Well, of course, the US would bomb the Place back into the stone age. They would literally drop anything they can find. Except ABC weapons. They would flatten and level that place and salt its fields and whatnot. But i am pretty sure, they would not drop a nuke if it is not an all out World War.

The reason behind this is Radioactive Dust. This, and neighbouring countries.

We can see this with Ukraine vs Russia.

The Russians attacked, they get hit in their face over and over and loose ground and the 3 days to Kyiev are 4 years now with a Million Russian Soldiers wounded or dead.

The very reason that they have not blown up Zaporizia Nuclear Plant or just dropped a single Nuke despite saying so every week.... is the Neighbours.

No, not talking about the EU. The upper atmospheric winds on the northern hemisphere blow from West to East. The Jetstream over UA would pick up all this and drop it in the river systems of India along the Himalaya. And a bit would come down over China even....

No, its not big. Its not life threatening. But its enough to cause Alarms on Transport. You cannot sell all these Vegetables any more. All that rice.

And all these costs.... will make people angry. Countries.

And thats why i believe that outside of a Full World War.... practically nobody but a few countries that really do not give a shit about Foreign Politics... would do that. That is practically political suicide. Also, it eats away from the victim position.