Like cryptography[1], rocketry has an inherent political character. If you disagree, then how would you feel about training a team of North Korean scientists in the type of long-range rocketry involved delivering a payload to a target as small as ISS?
I personally trust China with rocketry far far more than I trust North Korea, but "Do we trust this country with knowledge useful for killing large numbers of people?" is totally within the scope of a government to decide.
[1] http://web.cs.ucdavis.edu/~rogaway/papers/moral-fn.pdf
