It's an effective short term defensive strategy.
That's why I propose taking over TSMC Nanjing fab
Chips used in industry, such as factory and process automation, still use older processes. These are far more important for China as they are essential for manufacturing.
So called global chip shortage has nothing to do with cutting edge CPUs, GPUs and DRAMs. They have to do with the support chips that are still made with the older processes.
All these companies like TSMC, Samsung, Intel, etc,. they gradually abandoned the older processes for newer ones. Chinese swoop up on the older machines to continue producing mature chip designs. You put sanctions on SMIC and suddenly you lose an important producer of mature chip processes. Suddenly you get a shortage. Then Chinese companies started hoarding all mature and support chips stocks around the world, and those being produced in China are priority supplied to Chinese demand and not foreign. For this reason its no wonder why SMIC's expansion is for older processes.
TSMC building 5nm FAB in Arizona will do zilch towards this, as the problem is never on CPUs.
Media and blogger emphasis on cutting edge processes are vastly overrated, and those for mature processes are vastly underrated.