I am not far enough into my reading on weapons etc.to give a confident reply to Paul Midford and Jun Okumura, but I'd just make two points.
When I think of things I ought to worry about, it is not the likelihood of a nuclear exchange, or an equally devastating exchange of non-nuclear warheads, between US and China in x decades time, but the more immediate likelihood that NPT will give cover to an Israeli strike that will start an open-ended war in the Middle East.
I imagine that US-China will reach an explicit MAD equilibrium, nuclear
and non-nuclear, As with the ending of the last cold
war, when Gorbachev
let Germany go on the tide of a popular uprising, who knows? the growing preponderance of Chinese power might produce a popular uprising in Japan, fuelled by resentment at the Patron's highhandedness and a rediscovered cultural affinity with China,(see below) the crunch decision being a presidential rejection of the option of defending Futenma by force and imposing Maehara as a puppet prime minister.

Second point, PM's and JO's encapsulations of the driving force of China's foreign/military policy:

nationalistically driven expansionist power(PM) OR an expanding power with nationalistic constituencies, including a large military that cannot be seeing any value in downplaying its own external threats(JO)

I doubt that ambition for territorial expansion is a common preoccupation among Chinese. Rather China's "Rising Up" as Mao used to put it.Being treated with respect as an equal: not lectured at about being a "respomsible stakeholder"
See a fascinating review by Gerime Barme in HJAS 71.
2. Apparently a favourite phrase when foreigners get uppish is 臥薪嘗胆--to do what the defeated King of Giao did in 500 BC, sleep on brushwood and taste gall for10 years in order to prepare himself to take his revenge. It was also a popular slogan in Japan in the decade between Japan being chucked out of the Liaotung Peninsula by the Triple Intervention of 1886, and getting back in after they got their revenge against Russia in the Russo-Japanese War.

Ronald Dore