Too bad Trump will not be able to use that as a basis for either starting said war or winning the election in order to get more time to start said war.
Rest assured, if the proof turns out to be indisputable, the global reaction would be much worse than ANY war.
China would be marked as a pariah nation of terrorists.
I don't think ANY rational nation would be willing to continue on any kind of beneficial footing with China if it came out that they engineered a global pandemic.
It still might form a basis for war anyway but I would suggest that it would be far better for the entire world to bond together and punish China in far more creative ways first.
The first thing that comes to mind for me is a long term plan to boycott, divest and sanction in unison, and to migrate ALL manufacturing interests OUT of China permanently. Next, complete freeze on all assets, and all debts owed to China are to be hereby canceled and nullified.
A war is exactly what a nation like China would want because they can bankrupt numerous countries simultaneously by doing that. Win or lose, there is no "win"...it would drag on virtually forever or escalate to world war, possibly even nuclear, because any nation that would consider spreading a pandemic on purpose can't be counted upon to not go nuclear.
Nope, sour the tit and starve the beast, that's the smarter option in the long run.
Not even Japan, South Korea, Vietnam or any other nation in their sphere of influence would want anything more to do with them. It would hurt like Hell but think about it, it already DOES hurt like Hell right now.