[VK538FY]

Considering use cases, nuclear weapons aren't the ultimate weapon and a biological weapon could be employed in situations where nuclear weapons are inappropriate. Given the right biological weapon, a state actor (China, the US, or anyone really) could see the possible asymmetrical benefits.

Example: a purely theoretical biological weapon with low mortality but high economic cost and probably reduced military effectiveness. If I'm the country that uses it, I've taken measures to prepare and expect to come out ahead.

Whereas I observe 3 basic use cases for strategic nuclear weapons and only 1 (the last) is possibly comparable.

1/ game over for everyone, we'll launch left and right (Israel, I presume)

2/ I have enough nuclear weapons to make it not worth the price of bothering me (France, maybe China?)

3/ I believe that the combination of my delivery mechanisms and countermeasures give me a chance despite a generalized nuclear exchange (US, Russia/USSR).

Few know what really happened with respect to SARS-CoV-2. (I don't.) But I don't believe that the possession of nuclear weapons makes biological weapons completely 'uninteresting'.