There are more dimensions to this question than "are they behind or not?". In most areas, western technology and capability, given the will, still leads China.

There are more dimensions to this question than "are they behind or not?". In most areas, western technology and capability, given the will, still leads China. However, China excels at getting capabilities fielded and generally benefits strongly from a unified desire to leap ahead. They can often accomplish things that are potent, but executed in a cruder way than would the west. No matter though, if they can field the capability and it is "good enough". At least in the U.S., profound dysfunction and misalignment of incentives exist between high-level intent at the Secretary of Defense level and fielded capability. A historical trope was that the Chinese are not creative problem solvers or researchers, unlike the west. Anyone paying any attention to relevant technical areas should be thoroughly disabused of such thinking. There is some impressive conceptual work China contributes to the technical literature.