Not anyone else, but there certainly are other nations with similar capabilities.

USA is one of them - China is best suited for inserting "extra hardware" on a board as in this example, but if you'd want to insert similar functionality as some extra stuff in an existing chip, then USA could arguably do it easier than China.

Also, South Korea and Taiwan have immense role in the supply chain and can do similar large scale things as China.

However, yes, the lack of supply chain influence does make similar attacks much more difficult for a bunch of actors which are otherwise active in tech security area - Russia, Israel, North Korea, UK, etc.

NSA intercepted routers to do pretty much the same kind of hack. https://arstechnica.com/tech-policy/2014/05/photos-of-an-nsa...

5 eyes/Taiwan/some others could do in on the chip level I guess. Who knows what’s in the me or really all the SOCs...

But can't they take advantage of the vulnerability created by the chips, without caring about who put them there?