As things now stand, these are accusations, not proven facts. Suspicious allegations and accusations do not make a definite case.
China flatly denies these allegations. Thinking citizens will decide for themselves what to make of these denials, but they should be noted and carefully considered.
There are partisan political components to take into account when considering this whole business. Republicans have some strictly political reasons for pushing the case against China. Just as Democrats have some political reasons for making the least they can of the charges.
The alleged theft of important nuclear weapons technology began, so it appears, in the middle of the Reagan administration. And if the Chinese espionage turns out to be true, the Reagan administration has much for which to answer.
Also, the Bush administration courted the communist Chinese shamelessly, and much of the suspected damage may have been done on Presidents Bush's watch.
None of which excuses the Clinton administration, which might have known about the leaks as early as 1995.
As we await more facts, these are some points to ponder.