I'm not an expert at all so I have to wonder which core technologies were/are too expensive to duplicate for China? Afaik semiconductors represent the cutting edge of manufacturing technology; if China is able to duplicate (or even innovate, as demonstrated by "3d Logic folding") in this industry, I can't imagine how any other sectors would be too expensive to duplicate.
Who knows how far they progressed in lithography once it became clear that withholding technology would be the official state policy-- I heard the Chinese state got involved in developing EUV in a way comparable to the Manhattan project in scale and secrecy.
Who knows how far they progressed in lithography once it became clear that withholding technology would be the official state policy-- I heard the Chinese state got involved in developing EUV in a way comparable to the Manhattan project in scale and secrecy.