My read: China is seen as a serious geopolitical rival that the United States must beat in a shooting or Cold or AI or <insert here> war. As a result PHDs to China as an export would be a negative impact, not a positive one potentially.

America gave China its space (and ballistic missile) program when they deported Qian Xuesen in 1955.

That was a grave mistake, but there is no point in continuing to aid those programs with PhD exports.

When looking at China, this fable has been on my mind for the longest even as I’d hoped that market forces would liberalize it: https://fablesofaesop.com/the-eagle-and-the-arrow.html

Obviously, any hopes evaporated with China’s heavy-handed approach to Hong Kong.

Or their constant threats against Taiwan, or their oppression of LGBT people in their borders, or their genocide against the Uighur Muslims in Xinjiang, or their heel-turn into racialized nationalism (Han Chauvinism).

Correct, didn't think I would have to spell that one out.

Yeah, I read a lot of research papers from China too.