#257 – Tom Milton on how we could verify a US–China deal on AI

If the US and China agreed to pause frontier AI training, how would either side confirm the other was complying? Today, Tom Milton argues, the most likely answer would be to shut down data centres entirely. That would throw away everything else those chips do, and make any agreement far more costly to accept.

Tom is CEO of Amodo Design, a UK hardware lab building prototype tools to verify how AI chips are being used. He argues that verification is what makes a slowdown affordable: if a cluster can be shown to be serving only existing models rather than training new ones, most of AI’s benefits can continue during a pause.

Amodo’s pilot reruns a cluster’s inference on a separate verifier server and checks that all of its network traffic can be explained by the agreed model. AI companies are developing related tools: in its October 2026 Frontier Safety Roadmap update, Anthropic reported a prototype that runs on production inference and checks that outputs come from a specific set of model weights.

The field is small. Tom estimates that only about 50 engineers worldwide work on compute verification, compared with the billions of dollars the US spent on Project Vela to detect Cold War nuclear tests. And custom verification hardware has long lead times: it has to be designed, security-tested, red-teamed by both sides, manufactured, and trusted before anyone can rely on it.

If a deal is struck in a hurry, Tom expects it to be assembled from whatever tools already exist. Were that to happen next month, he says, the only option would be to shut data centres down entirely. That is why he argues the work needs to scale up now, with more people and resources from AI companies, governments, and funders, so that better options are ready as soon as a deal is needed.

Tom and host Tom Reed also discuss how an AI company might evade verification, lessons from nuclear and chemical arms control, and how AI is changing hardware engineering.

Learn more about Amodo’s work at ai-verification.com.

This episode was recorded on September 29, 2026.

Tom Milton, CEO of Amodo Design — which builds hardware for scientific research, biosecurity, and AI verification — argues that AI chips are a great place to start checking whether rival AI developers are really slowing down, and that the technology to do it is “tractable but not solved.”

How can you verify a data centre is only running inference?

Amodo’s pilot uses inference recomputation: a network tap copies a cluster’s front-end traffic to the verifier’s own server, which reruns the agreed model to check the outputs match, and any traffic it can’t explain points to an undeclared workload. On Tom’s account, the pilot runs on about 30 to 32 H100 and H200 GPUs. Because the verifier currently needs the model weights, he expects real deals to rely on zero-knowledge proofs instead; these carry many orders of magnitude more overhead, but checking one packet in 1,000 could give reasonable confidence.

Chemical weapons inspections offer a model for AI verification

Inspectors from the Organisation for the Prohibition of Chemical Weapons (OPCW) give 48 hours’ notice before a standard inspection of a declared site, and use mass spectrometers with a confidential mode that returns only a pass or fail. AI verification needs similar confidentiality to protect model weights and users’ input and output tokens, Tom argues. The effort gap is large, on his estimate: maybe only 50 engineers in the world work on compute verification, while the US spent billions of dollars in today’s money on Project Vela to detect nuclear tests.

Verification tools must be ready before a rushed AI deal

A real deal might be put together in two to 20 days, Tom expects. If a deal happened next month, he says, zero hardware verification mechanisms would be used; the fallback would probably be shutting down data centres, sending in auditors, and using infrared satellites. Long-lead-time work should start now, including Amodo’s network certifier, an FPGA chip that keeps a cryptographic log of network traffic and still needs security testing, red-teaming, and scaled-up production.

Why AI lab researchers should work on compute verification

What would most help Tom sleep at night is dozen-person verification teams at the major AI developers. Given how often lab staff cite verification in their theory of victory, an outsider would expect 10 multihundred-person teams, but he suspects the real effort is much smaller. In his view, a talented safety or security researcher who started today would probably be one of the best five people in the world working on verification by the end of the year, because lab staff know the frontier and infrastructure, and are who leaders will ask when a deal is on the table.

How good are AI models at designing circuit boards?

Claude Fable is the first model that could contribute to hardware design at all, Tom says, roughly where GPT-3.5 or GPT-4 were for software. A power-monitoring circuit board that took an Amodo engineer 10 to 30 hours to design, Fable produced in one shot; it works, but is extremely ugly and hard to debug. He puts Fable 5’s hardware time horizon at something between 10 and 100 hours, and finds models OK at schematics, poor at layout, and very bad at routing.

This summary was drafted with AI from the episode transcript and reviewed by the 80,000 Hours team.

Our production team includes:

  • Video editors: Josh Alward, Dominic Armstrong, Jasper Luithlen, Milo McGuire, Luke Monsour, and Simon Monsour
  • Producers: Elizabeth Cox and Nick Stockton
  • Coordination and support: Katy Moore and Lou Moran
  • Camera operator: Dominic Armstrong

Music: CORBIT

Articles, books, and other media discussed in the show

Tom’s work:

Other work and organisations in this space:

Lessons from the nuclear model:

Other 80,000 Hours podcast episodes:

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