There is a major trump card that can be played against the Chinese, OIL. Release another bio-weapon and we shut off your oil and crash your economy.
China's domestic oil production has been falling since about 2013. It currently imports about about 75% of its oil. The weakness of the Yuan relative to the Dollar drives up the cost of importing oil as oil prices are quoted in $US.
About 60% (2.5+ mbpd) of China's oil imports come from the Middle East. That oil has to pass through TWO relatively narrow straits. They are the Strait of Malacca (Singapore) and the Sunda Strait (Jakarta). Anak Krakatoa volcano sits in the middle of the Sunda Strait.
Even the suggestion of military action by China would drive shipping costs for that oil through the roof. In the event of actual hostilities, it would require a relatively trivial effort to shut these straits to tankers bound for China.
WWG1WGA
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)
There are a lot of cards that can played against the Chinese, and as you rightly point out, oil is one of them. For all their apparent strengths, the Chinese have a lot of vulnerabilities. One of them is that they put all their eggs in the Deep State basket. Their tremendous growth over the last 20 years has been based on an artificial system set up by the Deep State - a system of currency manipulation, unfair trade deals enforced by the UN, etc. Those seemed like strong pillars at one time, but POTUS is showing how easily it can all be dismantled.
The Chinese government is also vulnerable to civil unrest which has the potential to bring the government down. If Trump were to reveal to the world the degree to which China not only inflicted the coronavirus onto the rest of the world, but the degree to which they inflicted it on their own people, it could cause some sort of civil war in China.