One thing to remember is that "self-sufficiency" is all relative. Technically anyone can be "self-sufficient" by pursuing autarky - North Korea is relatively "self-sufficient" today. But in the context we are talking about, it means self-sufficiency at the bleeding edge of technology, or very close to it. The significance of this is that your country's technologies are competitive. Thus "self-sufficiency" is not tied forever to any particular node or technological level. Rather it is a measure of your country's ability to stay at the leading edge of technology. Thus the important thing for China is to build up the institutional and cultural environment conducive to scientific advance and innovation such that it can stay competitive with the US-backed alliance in the long run, and not just any particular technologies. If China has the institutional and cultural environment conducive to long-run R&D, it will be OK and the technological advances will come no matter what. But there are many elements of this ranging from ability to attract talent, to the correct use of markets, and the correct use of government investment.