It's more of a weapon system and AI-model issue. Think of Russians using missiles filled with Chinese-manufacturered electronics rather than US ones. Now US sanctions are less effective (even in the face of all the smuggling that happens anyway).

In the same way, think of China training militarily useful AI models on hardware they no longer need the US to supply. Things like models for more effectively deadly biological or chemical compounds. Or even targeting and decision making algorithms. In a war, they would be able make their own hardware to support such efforts, rather than being reliant on the US.

Ultimately, it doesn't matter in times of peace, or if we were all able to get along with each other. But seeing as everyone is trying to have an advantage on all other potential enemies, this presents a problem.