Also if it’s not put it in action but rather discussed publicly, that’s just helping the society prepare and evolve.
Free speech is a principle to guide laws, not a law unto itself. Protecting speech that makes people less free is oxymoronic.
Your nearest research university library probably holds publications about the effects and synthesis of chemical warfare agents, like Some aspects of the chemistry and toxic action of organic compounds containing phosphorus and fluorine by Bernard Charles Saunders: https://catalog.lib.uchicago.edu/vufind/Record/587946
Which is also scanned and available online: https://archive.org/details/B-001-026-884-ALL
[1] https://en.wikipedia.org/wiki/Born_secret
[2] https://en.wikipedia.org/wiki/United_States_v._Progressive,_....
Certainly. However, here they have identified and published not the discovered molecules but only the identification process (and only in fairly broad strokes, at that), and shied away from working further on synthesis (we know enough to state that synthesis would be possible and practical for nearly any candidate molecule).
Sure, as a society we can expand ethical guidelines to some sort of "thou shall not optimize for toxicity", but enforcing it poses some serious challenges, not least of which is the fact that this has demonstrated that the process works even with fairly innocuous and public training data.
Expect to see a bunch of funding for research into technologies around toxin identification and detection, as well as the rapid creation and synthesis of antitoxins and other prophylactic measures (cheaper filtering, maybe). Perhaps even eventual (as in a decade out at least) "hardening" of organisms against toxicological weapons (possibly positioned as research into the mechanisms of acquiring pesticide resistance and similar).
I'm pretty sure that whatever a private individual figures out on his own is not "classified", since it's not a government secret. Is there actually a US law banning people from even talking about WMDs?
Are you going to spell out in the law exactly what people aren't allowed to research? You've just implemented a holding pattern while giving them a road map on what to research. So your holding pattern is going to be set up to buy you x number of years, where you assume it will take your adversary x number of years to fill in the gaps on the map you just gave them.
Is that enough?
Security and espionage laws are often not directly enforceable. Their value is to "pile on", adding severity to related matters, such as charges committing or aiding past terrorist acts or planning therefor. Ideally the threat of direct prosecution for a crime would deter possible perpetrators, but making penalties more severe and extending incarceration are useful roles for laws too.
That applies to government employees, who willingly agree to be bound by classification. I think that if someone outside had the information, they could publish it (probably a very bad idea).
Also, the press has a right to publish classified information.
If you can actually afford your rights, be my guest!