Why do you think they don't want to do it? I find that a weird statement, and your given reasons don't make sense to me. This is one of their core programs, and as part of that have taken over some IP via espionage programs. China is actively trying to build one for quite some time now.

  > people overstate complexity of ASmL machines. They are not impossible to make or use, specialist work sure but its possible. The only reason why no one does it is: 1) IP laws, 2) Costs

The real reasons are: enormous complexity, lots of original research involved, deeply specialized supply chains. Recreating that takes lots of time and money. Even if you cut corners and steal IP. So that leaves China with 'time' as the real impediment. And who knows, AI will be a boost to get to that goal?