Practically speaking, providing an exploit to the Russian government vs the US government - that would be a different effect, no? How would you justify providing the exploit to the North Koreans, or the Iranians?

There is a very practical morality at play here. The Chinese government runs protesters over with tanks, imprisons people without cause, attacks their neighbors without cause, etc. Would it be a good thing to aid such a government?

Putting all governments on the same moral plane is counterproductive and nonsensical. Not providing important information to your own government so that they can secure the very systems that protect you - that doesn't seem very practical.