Thoughtful and I hadn't considered covid as a strategic defeat, but that is certainly true. Without the US, we can't even fight the old wars of the past and future wars we seem to believe that virtue and doing the right thing is more important.That also assumes that wars of the future will look much like wars of the past.
Future conflicts against peer opponents are unlikely to be heavyweight square-ups given the potential to escalate, and current force capabilities have shown that they are more than adequate for pointless and ineffectual adventures in hot places. The real threats are going to come from social subversion, cyber, bacteriological and Sudetenland-style agitation combined with a version of bite and hold using SF/proxy forces, as per the Ukraine. And there's no evidence that the implications of that have been thought through, let alone mitigated.
Western economies and their supporting media and political structures are breathtakingly easy to subvert if you have deep pockets - and China knows how to spend its cash. COVID may have been accidental but it won't have escaped notice that it's effectively been a major strategic defeat for the West. Something of limited lethality but which can cripple an economy would be well worth being able to replicate, not to mention representing a new way of thinking about bacteriological warfare.
A few traditional battalions more or less will make little practical difference.