Should a handful of men be entrusted with the world’s most potent new technology? Five geeks so famous that they can be identified by their first names—Dario, Demis, Elon, Mark and Sam—exercise almost godlike command over the artificial-intelligence models that will shape the future. The Trump administration has stood aside even as those models have gained jaw-dropping capabilities, convinced that unfettered competition between private firms is the best way to ensure America wins the  AI  race against China. Until now. Suddenly, America’s free-wheeling treatment of  AI  looks as if it is coming to an end. The reason is that the models’ dizzying progress also poses a threat to America’s own national security, unnerving members of the Trump administration previously more inclined to worry about overregulation. At the same time, growing resentment among American voters is turning  AI  into a political lightning-rod.…