“Any war against either of these two nuclear powers would immediately devolve into lobbing hundreds of nukes at each other from long range”
That sounds so DU; illogical, simple minded, and defeatist. What makes you think a war with China turns into a nuke fest? You really think the leaders of China want to rule over radioactive waste?
What the heck is defeatist about being realistic about the likelihood that a full scale military confrontation of two massive nuclear powers would rapidly escalate into a full-blown nuclear war? Do you really think that the Chinese leaders are sane enough to withhold their most potent weapons at the very moment they're going down to defeat? They would have nothing to lose, since they would be dead or defeated either way.
What's really simple minded is the belief that full scale war between nuclear powers could ever be conducted with some medieval-style code of honor or enlightened self-interest that would keep nuclear weapons from the battlefield.