- Most countries have little to no uranium deposits and so have to be able to find a uranium-producing ally willing to play ball.

- Production of enriched fuel and R&D are both outrageously expensive, generally limiting them to state actors.

- Enrichment has massive energy requirements and requires huge facilities, tipping off observers of what you're doing

Despite all this and decades of strong anti-nuclear proliferation international agreements India, Pakistan, South Africa, Isreal, and North Korea have all developed nuclear weapons in defiance of the UN and international law.

In comparison the only real bottleneck in proliferation of AI is computing power - but the cost of running an LLM is a pittance compared to a nuclear weapons program. OpenAI has raised something like $11 billion in funding. A single new proposed US Department of Energy uranium enrichment plant is estimated to cost $10 billion just to build.

I don't believe proliferation is inevitable but it's very possible that the genie is out of the bottle. You would have to convince the entire world that the risks are large enough to to warrant putting on the brakes, and the dangers of AI are much harder to explain than the dangers of nuclear weapons. And if rival countries cannot agree on regulation then we're just going to see a new arms race.