In the nuclear world in which China has DF-41, the "MAD" doctrine is still well in place. But a mystery virus affords far more "plausible deniability" for the US. Thus achieving the goal with less fear of attribution and thus retribution. Instead of directly confronting China in the SCS militaristically immediately, maybe they think a better way to take China down a notch or two would be the use of "other means" to an ends...
Science and technology in the world has come a long way since the days of Westerners giving Native Americans blankets laced with smallpox to "thanksgiving" them. It is the human condition to be risk/loss adverse. A nation that would stop at nothing to achieve Maniesft Destiny surely wouldn't have any qualms of preserving its hegemony at all costs on the way down.
Similiar to the arms stockpile, I would think China would be well served to have a secret stockpile of bioweapons as "credible deterrence". Even if this had nothing at all to do with foreign external forces and was very coincidence just "natural" and "bad luck", then China still needs to recalibrate its posturings in that there are nations that will not let a "crisis go to waste" and will take full advantage of China while it is down. Steve Bannon was hoping to "break the back of the CCP" by cutting off China's supply chain, and was hoping the HK roits was going to catch fire in the rest of the mainland and force the CCP to lose control making it easier to do an opportunistic regime change.
So China needs to watch out for the far fetching implications of the impact of this new virus regardless of whether or not it was man-made. China should at least stay vigilant and have a credible deterrence contingency plan in place...
I'm sure both China and US have their own red lines. If the US had any involvement in this new virus, if China finds any credible evidence, then there are a number of things China can do besides retailiting with its own bioweapon... for example, we all know the Trade War is not about trade, but wanting China to slow down in terms of hegemonic rise... for example China could simply start building Huangyan Island in the SCS, making a move that would seal the US fate as the "falling empire". If China militarizes the island it would give China total control of the SCS region, so China can declare ADIZ over SCS, America would be pushed back to Guam, and it woulld be the beginning of the end of the petrodollar hegemony (which never could have lasted forever anyway but it would push it up along the timeline to make it collapse that much faster)
Some have said that well the virus is RNA single stranded which makes it harder to target any race specific without mutations losing the specificity over many infections cycles. And that if it were double stranded it would make it that much easier to create vaccines for and kill/contain. But I believe in this case it is about maintaining "plausible deniability" whilst not crossing any hard red lines in case attribution is established in the future. A virus outbreak that dings China's GDP by 2 to 3 % in 2020 is not comparable to an end of civilization event that wipes out 90% of the Chinese population, for example. Whatever blowback or collateral risk is considered acceptable levels since it was deployed to China's central Wuhan, naturally China has a self interest in containment, and the vast majority of the damage will be internal to China. It may have been engineerred as race specific single stranded RNA and knowingly by hostile forces that predicted by the time it lost its race specificity that China would have already contained it. Hence "mission accomplished" with little attribution and minimal blowback. What better way to undermine China/CCP than to have its population grow resentful of or turn against its very Government!? Already Western media is talking about how Chinese are filthy and if it wasn't for eating rats, bats, dogs, etc this wouldn't ever have befallen. Perfect cover for re-enforceing racists stereotypes for the ulterior motives of containing and isolating China, and that of Chinese culture, and Chinese ideology on the world stage.
