The day Mythos class models are open sourced will not be a good day. I don't think you understand the impact that will have on the world and on cyber defenders everywhere. It will be pure chaos.
Even if you don't think Mythos-class is the bar, open source has to stop at some point, you don't hand everyone a superweapon.
Handing every skiddie and nation state and APT and hacker group access to Mythos does not help cyber defenders
Even if you don't think Mythos is a big deal: At a certain point models become smart enough as to be dangerous, and you don't give everyone a superweapon. Open source has an end of the line sooner or later.
Luckily, Anthropic has no such monopoly, so the point is sorta moot
I'd wager 99.99% of humanity would not want to start a nuclear war by vaporizing millions of people, animals, etc. with a nuke. They'd back away slowly and figure out how to ensure it was safely disposed of so they didn't need to be near it or worry about it.
A very small number of people would like to have a nuke with which to harm other people.
Some of those people even probably got that way because of actions taken by people saying things like "if we don't do it, somebody worse will" and "we are the only ones who can be trusted to control this power"