True, but besides wars there are other dangers, e.g. USA does not declare war when they apply "sanctions" randomly, under the legal theory that they can dictate how anything that includes some piece of US origin may be used by its owner.

Since that theory began to be used, anyone outside US has become anxious to become "sovereign", i.e. to stop using anything about which a foreign state can claim to have rights.

It's a nuclear weapons thing. Basically you want your entire nuclear weapons supply chain infrastructure to be in your own country. These days that also includes super computers to do simulations on what happens with your aging asrenal (just look at how many Top 500 supercomputers are at national labs like Oak Ridge, LLNL, or Sandia). Japan doesn't technically have nuclear weapons, but they're rumored to be "a screwdriver's turn away", or practically within a few weeks of having a weapon. That posture itself requires even more simulation just to be sure you can make good on that.

The AI stuff is basically "well sure, these are really good at distributed matrix math, why not?" hoping to get better volumes and make the program cheaper internally.

And they're working on getting chips fabbed in Japan too now that IBM sold their 2nm process to Rapidus, but that's probably successor to these. Maybe 2028? In the meantime there's still more nuclear simulations to run than there is compute to run them.

Isn't the supply chain on advanced semiconductors ludicrously extended?

Wafers rare Earth's, specialized equipment, etc?

It means it's not beating B300 in FP4 TOPS.

> Doesn't really make sense to me. The whole "sovereign" thing is to basically say you won't be screwed if you go to war with a country tomorrow because you are dependent on their supply chain.

I don't think it is that basic. If anything it's probably more about having protection from trade and sanction threats, and insulation from shortages, supply chain problems.

> Nothing about this changes that IMO. They're still getting the chips fabbed somewhere else and run the same risks.

It certainly changes it. Chip design is of enormous importance and the technology leaders there are concentrated in the USA.

Silicon manufacturing is a different thing. Japan is also trying to bring up sovereign leading(ish) edge manufacturing. Obviously you keep peeling the onion on everything though - to do digital logic they need EDA tools and quite possibly IP blocks for PCI and DDR and so on. To do manufacturing they need scanners from ASML and a process design from IBM and so on... It doesn't mean that because they can't do everything from the ground up that it's pointless. At some point they need to import coal and iron ore and bauxite.