Look I'm not saying we officially support the people who overthrow the regimes, we just create the means for them to do it. Plus I've seen projections that if the war lasts over three years that both will be on the ropes. The opportunity here I say is to let them bring themselves to their knees, than we will strike.
Also to anyone saying we give the Japanese any aid while this nuclear disaster happens, we cannot trust them, and to those who say they are dying, let them die.
I for one think the projections are wrong... China has been wracked with war since the First Opium War against Imperial Britain in 1839... 172 years... Japan's war machine has long since run past the point where ANYONE else would have thrown in the towel and yet they still have the second largest military of the Pacific powers (second only to China of course) and the third largest economy (after the US and the Philippines). Any war China starts with Japan is going to last no matter how it turns out.
I think China CAN win now that the earthquake has shown how 'brittle' the Japanese system can be, but like every war fought it won't come cheaply or quickly. I think the Chinese seem to be expecting such a victory, forgetting their own and their shared history with Japan.
Keeping the Fukushima Daiichi plant from melting down further is just good business and good environmental policy. The last thing anyone wants is another Windscale meltdown and the reactors are an old US design gen 1 and 2 reactors (no one except us and the ANZACS care about upgrading the things to gen 3 and above
And we do sell military equipment to both nations. Heck the Japanese Sendai class subs are just the renamed old Los Angeles class and the GR-12 fighters the Chinese use are the export version of the J-29. The US isn't called the 'world's arsenal' for nothing...