You can self isolate without quarantine measures in effect so your point isn't that strong to me and you are ignoring that one of the biggest destabilising forces in history is economic downturn. US-China relations have been bad for a while now and both sides are throwing blame at each other as a populist policy (China has a US origin story allegedly). If this pushes the economy in to a global depression who knows what will happen s few years down the road. Taiwan, Korea, plenty of places that could erupt if things become politically unstable - both in the US and China.