It is not like even you are open all US research to one country in an instant, they would be able to build their own next decade.

China did a really good job figuring out the know-hows and had their domestic team geared up for the job. That is nothing to be dismissed, like tired 'China can't do shit without stealing our technology' circlejerks would like to indicate.

When you look at the history of space travel. One of the first space programs (NASA) originated from Germany developments. North Korea nuclear weapons from Soviet undercover collaboration. Not familiar with specifics for your claim above, but just stealing is a miniscule part of what is really required for this type of effort

You mean the point that history[1] tends to repeat itself[2]?

[1] https://www.history.com/news/industrial-revolution-spies-eur...

[2] https://en.m.wikipedia.org/wiki/Operation_Paperclip

In the context of for-profit business I wholeheartedly agree with you, but in the context of space exploration, if there is research about how to go to the moon and Mars that can be "stolen," isn't the moral culpability on whatever entity is hoarding that knowledge?

Or is going to the moon and Mars the achievement of certain parts of humanity, to be kept secret from other unwanted parts of humanity?

I think some evidence is needed for the accusation that they stole significant space technology research.