Government can try what it wants, we've done this before
It's a fundraising move. OpenAI becomes concerned about how dangerous the things it's selling are when it comes time to fundraise. This nonsense doesn't work that well in America anymore, in part because our politicians bite the bait and then start regulating, which Altmen et al don't want, but you can absolutely get a term sheet in the Middle East and Asia by linking yourself to the national security budget.
In 2022, a survey of AI researchers with a 17% response rate found that the majority believed there is a 10 percent or greater chance that human inability to control AI will cause an existential catastrophe.
Altman, 2015: https://blog.samaltman.com/machine-intelligence-part-1
Bostrom 2014: https://www.goodreads.com/book/show/20527133-superintelligen...
Stephen Hawking, 2014: https://www.bbc.com/news/technology-30290540
Take your pick.
Are Geoff Hinton, Yoshua Bengio, and Douglas Hofstadter also marketing?
Maybe you can't have such a big explosion with conventional weapons but you can just use more.
The problem is contamination.
Invisible and deadly
It's absolutely the explosion. (And fires.) You can make a similar boom as historical (not modern) nukes with conventional weapons, but not in a form factor that fits on the tip of an ICBM.