Microsoft’s fastest-growing AI market is the one America fears most

While American lawmakers warn that Chinese AI poses an existential threat to US dominance, Microsoft has quietly turned the country into a billion-dollar business, selling OpenAI’s models to the very firms Washington is wary of. ByteDance, the Beijing owner of TikTok, has been Microsoft’s single largest AI customer in recent years and is on track to spend upwards of $1 billion a year on its AI and cloud services, Bloomberg reports.The catch is what ByteDance mostly buys: OpenAI’s GPT models, piped through Microsoft’s Azure cloud, in a market OpenAI itself won’t go near. And it isn’t alone. Ant Group, Meituan and Tencent are also big spenders on AI through Azure, leaving Microsoft as the one company channelling America’s best models into the hands of its biggest tech rivals, distillation fears and all.

The one company selling American AI where its makers won’t

OpenAI and Anthropic both refuse to sell their models to firms in China, citing fears of intellectual property theft and harmful use. Microsoft is the loophole. Its unusual partnership with OpenAI lets it set its own China policy, so it ships the GPT series there anyway. It sells a spread of other models too, though pointedly not Anthropic’s.What these firms do with the models is murkier, though much of the spending reportedly funds their push outside China. All of them train their own AI as well; ByteDance, for one, runs a popular Chinese chatbot called Doubao.

China is where Microsoft’s AI revenue is growing quickest

Inside the company, this reads as a win, not a worry. At a July 2025 sales meeting, then chief commercial officer Judson Althoff told staff that Azure’s AI revenue was climbing faster in China than in any other territory, roughly tripling in the year to June 2025 after a 400% jump the year before, according to a transcript reviewed by Bloomberg.“The world’s most elite AI solutions are being built on the western coast of the United States and the eastern coast of China,” Althoff said. “The one company bringing those two places together is Microsoft.”In context, the business is tiny. China made up about 1.5% of Microsoft’s total revenue in 2024, president Brad Smith told Congress. But it lands at an awkward moment, with US executives and lawmakers calling China’s AI drive an existential threat just as Washington tightens the rules on who can reach America’s most powerful models.

Why OpenAI keeps complaining behind closed doors

OpenAI has privately grumbled that Microsoft isn’t doing enough to stop Chinese firms from copying its models, a process known as distillation, according to Bloomberg. Microsoft points to automated monitoring and says it only sells to established companies, not individual developers. Even so, Chinese customers face no extra scrutiny, and training on synthetic data is hard to catch.Some limits do hold. Under its OpenAI agreements, Microsoft won’t host the models in its Chinese data centres near Beijing and Shanghai, fearing the IP could walk. Customers reach them over the internet from facilities elsewhere instead, such as Singapore.Which leaves the question Microsoft can’t answer: what is its biggest AI customer ultimately training?