The proof is reference to China. Just like if one were to say we should stop technological collaboration with India that would be enough.
Considering both Governments are notorious for reverse engineering things they only have on the condition they wouldn’t reverse engineer it, both Governments are actively hostile to the “west”, and both Governments are actively helping a war criminal get his hands on things he shouldn’t I think it is safe to say no one needs much more of a reason other than a history book to say “Maybe we shouldn’t be trading and collaborating with hostile nations”.