When Xi Jinping left Washington on 25 September, the headline deliverable from his three days with Donald Trump was not about tariffs or rare earths or Taiwan. It was about artificial intelligence. The two governments announced a "Super Intelligence Dialogue" and, more concretely, a bilateral channel to notify each other about AI incidents with national security implications: a hotline for the moment a model does something neither capital can control. Then, less than a week later, standing before a room of American tech chief executives, Trump ruled out the very cooperation the summit seemed to promise. "A lot of people say, let's do it together with China," he told reporters, "but then they're going to be able to immediately gain access to things that we know that they don't know." The distance between those two moments is the real story.
The mechanics of the agreement are genuinely novel. According to accounts pieced together from the summit readouts, the groundwork was laid in New York on 20 September, when Treasury Secretary Scott Bessent and Vice Premier He Lifeng agreed to a formal AI dialogue, with Shenzhen floated as the venue for a follow-up in November. The incident hotline is meant to work in real time: if an American system breaches Chinese infrastructure, or a Chinese one breaches American infrastructure, or an agent simply slips its leash, each side can pick up the phone. Given a year in which AI agents have repeatedly broken out of their sandboxes, that is not a hypothetical worry. It is an attempt to build a fire alarm before the fire.
The trouble is what the alarm leaves out. As analysts at the Observer Research Foundation noted, US officials made clear that export controls on advanced chips are not part of the dialogue, and the summit produced nothing on jointly regulating frontier models or on keeping humans in control of nuclear decisions, a principle Biden and Xi had at least gestured at in 2024. Washington wants crisis management without ceding any technological leverage. The hardest question, what actually counts as an "incident" worth a phone call, is left undefined, which in a relationship this distrustful is less a loophole than a chasm. Earlier US-China hotlines have a poor record: a military link set up in 2008 has at times simply gone unanswered.
What makes the story sharper is how differently the two leaders framed the same handshake. Xi described a race to catch up rather than a contest with a single winner, and repeated that AI must stay "under human control," positioning Beijing as the responsible steward and champion of multilateral governance. Trump offered the opposite: a zero-sum contest America is "leading by a lot" and intends to keep leading, complete with a jokey aside that Xi would happily "take every data center that we don't want." At the United Nations he had already dismissed any "globalist" scheme for governing the technology. One side is selling cooperation as its brand; the other is selling dominance. The dialogue survives only in the narrow space where both find it useful to be seen talking.
Behind the theatre sits a domestic consensus that is stranger than it looks. As Newsweek's AI Policy Scorecard showed, national security is the one AI issue where American lawmakers of both parties cluster together: it is easier to agree on beating China than on anything about regulating AI at home. Senator Ted Cruz called the race "the single most important economic question facing America today," warning that the winner's values, surveillance or free speech, would "suffuse" the technology. Yet as one former State Department official put it, you cannot hold a "beat China" consensus and a "slow down AI at home" consensus forever without the contradiction surfacing. The summit exposed exactly that tension at the diplomatic level. Both governments have real reasons to want a channel open, from ransomware gangs to rogue agents. Both have stronger reasons, for now, to keep the other at arm's length. The hotline exists. Whether anyone answers it is the question the next round, due in November, will begin to settle.