This. Will. Never. Work.
This research game is a zero-trust iterated game. Any defection carries the benefit of possibly being permanently valuable. There will always be defections. OpenAI defected WHILE THEY WERE pushing to slow.
The cost to the US of deciding to slow is so massively harmful that it is wrong to even put this idea out in the public zeitgeist; it may somehow become a thing that US legislators believe they can accomplish. They CANNOT accomplish this, because the fundamental economics and possible outcomes make it mandatory for any strategic adversary to work as hard as possible to defect.
The proposals here imagine a global panopticon surveillance state overseeing all research and chips as a 'reasonable' solution. EVEN IN THAT (terrible) state for the world, we will have effective defection.
Like it or not, the world is on this train, and the only sane thing to do is to fully support high quality ethical research groups and firms as they get up the learning curve of this technology.
Variants of this idea in AI 2030 included burning some of the US lead to get some nebulous safety metrics improved - also insane. Any slowing allows strategic adversaries time to catch up with very different alignment goals.
Do I like this situation? No. Are the people signing these things just fully in denial about the game theory and the stakes and the behaviors of strategic adversaries? Yes, yes they are.
Why not? Slowing down / halting biological weapons research mostly worked. Yes there have probably been modest sized defections here and there, but the pace of bioweapon development is a crawl compared with (a) what is possible with science already, and also with (b) the pace of bioweapons development from 1910 to 1970.
Bioweapons don't make money. AI does. The two are therefore not comparable.
The only thing it might accomplish is allowing OpenAI / Anthropic to squeak out an IPO before the market realizes AI will become a commodity and the massive profits these companies are promising will never materialize. They aren't in denial about this open letter's futility in terms of actually reducing the pace of AI, that's just not their goal in the first place.