Jet engines are far more high-tech than most people imagine, but I'm not convinced this is evidence of some inherent Chinese weakness. The obvious explanation is that China started much later in an insanely difficult field.

They are narrowing a gap measured in decades. The article explains the difficulty well, but it doesn't convince me that China can't eventually (again, given enough time) build good engines, especially for domestic military use.

Same for semi-conductors, IMHO.