Historic precedence indicates humans are capable of any conceivable action. Given that understanding it follows that a nation should be willing to consider uncomfortable things in order to protect itself against the actions of evil men and women.
Here is a briefer on binary bio-weapons as it pertains to pathogenic viruses and activation proteases.
Historically the term "binary weapon" referenced chemical warfare, where two component chemicals are mixed during delivery to complete the chemical used as the weapon. That term is used here in the context of biological weapons.
A pathogenic virus uses a specific activation protease, or number of proteases, to complete the chemistry in each step of pathogenicity. These specific activation proteases can be components within the natural environment of the target cell or be introduced; but in either case must be at a high enough concentration to overcome the protease suppression produced by current immune response.
In the case of SARS, the specific protease(s) required for attachment, as well as cell entry, have been identified. Proteases, inhibitors, and gene editing kits specific to this virus clade are commercially available.
Bioweapons are a long-studied method of warfare; but only in the past few years has it been possible to create viable chimeric viruses while amplifying pathogenicity. It appears Chinese and US researchers cooperatively pursued such research. It is possible the resulting transfer of knowledge, technology, and product has enabled the design of binary bioweapons that use an activation protease and a transmissible virus as components.
In application as a weapon the target population would first be exposed to a component virus. Perhaps a common virus held in check by protease suppression created by immune response. The other binary component, the activation protease(s), would then be introduced into the environment at levels high enough to overcome the protease suppression produced by current immune response; with the actors protected by prophylactic protease inhibitors and isolation.
In human immune response it can be imagined that given enough time, the immune system would clear the virus component of a protease activated bioweapon, where any exposure to high levels of the activation protease would be absent the other component required for pathogenicity, unless some means was used to keep the virus active in the target population.
Given modern world state relations and technology the probability of a targeted bio-attack by a nation state upon another appears to be quite low. It does not preclude criminal actors within nation state apparatus using nation state assets to carry out an attack. There are many possible motives for such an attack, those possible motives would not exclude simply making money.
https://pmc.ncbi.nlm.nih.gov/articles/PMC3889862/
https://www.nature.com/articles/s41589-022-01059-7
https://virology.ws/2020/02/13/furin-cleavage-site-in-the-sars-cov-2-coronavirus-glycoprotein/
https://www.life-science-alliance.org/content/3/9/e202000786.abstract