Nothing. There might be some condemnation and hard-wringing and perhaps even a few harsh-sounding words ... but nothing else. No Chinese sell-off of USD or bonds (why bother? how would that profit China's elites?), nothing from Putin, nothing from anyone. No one will do a damn thing.
Of course, if the US were dumb enough to use conventional forces or attempt any actual fighting, it would get whupped in short order, because you need a functional military to do fighting, as opposed to just blowing up people from a safe distance.
That's why it will be tactical nukes.
And no one will do a damn thing about it.
If you all thought the invasion of Iraq and subsequent whoring by organizations such as the BBC was completely unbelievable, and I certainly did, wait until you see this.
Gotta remember that Bush is a classic narcissist, at the end of his term, big Napoleonic complex, worried about his "legacy" one hundred years from now. I could be wrong, but I'm guessing using nukes, unprovoked, couldn't be spun, even in this moron's self-absorbed mind, as being the stuff of a positive historical review for posterity. Fai de bèn a Bertrand, te lou rendra en cagant
I'm not so sure it'll be tactical nukes.
Also, they must know that from this study that Earth-Penetrating Nuclear Weapons would not be very effective and would in any case produce huge radioactive fallouts (which, besides killing thousands of civilians, could affect American troops in the area). "Dieu se rit des hommes qui se plaignent des conséquences alors qu'ils en chérissent les causes" Jacques-Bénigne Bossuet