I do not disbelieve that China will attack the U.S.. However, this is a bunch of BS. If they are developing weapons to not kill the Chinese, they haven't done a very good job, as Chinese have mostly been the ones dying with the recent virii (soon they will make their way over here, but that usually take a year or so).
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I say it will happen, because we're forcing the issue with the way we use and guard our energy resources. China and Russia (now openly allies) have been on track for preparing for an industrial crisis for some time, with China being at it a bit longer. When they take Taiwan back, it will open a big can of worms.
Also, I cannot imagine a successful genetic weapon. Given that most people's blood would be 'not pure', and those that are most deserving of producing new humans will defintitely be 'not pure', I have a hard time seeing a gene-based WMD doing anything but destroying most of the humans around, including those it was not supposed to. It would also destroy a pool of genes--human evolution--of hundreds of thousands of years worth of mutation and selection. The best way for mass killing, concerning human survival and advancement, would be to kill evenly over all breeds of humanity.
If anyone were stupid enough to make virii for it, we'd surely be in for some nasty times. In the real world, such a thing would find an avenue for mutation, and eventually thrive where it was not meant to. I doubt the Chinese would be stupid enough to do that, even if they felt they had reason for it.
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