Emmanuel Macron hosted a summit on artificial intelligence in Paris that was advertised as a chance to speed up the development of the technology, while ensuring that “nobody is left behind”. The French president announced private-sector investments and urged Europe to “resynchronise with the rest of the world” on AI. But America and Britain spoiled the party by not signing the official declaration, which mentioned international governance, and was signed by China. J.D. Vance, America’s vice-president, warned against “excessive regulation”, which could stifle innovation, and making deals with “authoritarian regimes”.