The US-China AI competition faces a dilemma. Both countries see artificial intelligence as a source of economic, scientific and strategic power, so neither has much incentive to slow down. Yet the more capable and autonomous AI becomes, the more important the question of human control. Last week’s summit between US President Donald Trump and Chinese President Xi Jinping brought that tension into the open. Trump wants to leave AI “exactly where it is” rather than add new guardrails, while Xi...