Russia retains an (rapidly diminishing) edge in certain areas of space. One of them is engine design. China is still keen on buying the best Soviet engines, namely Energia's RD-170 and its variants but of course Russia is less than keen on parting ways with them.
Even CALT, the major launch vehicle provider in China, admits it will be well into the late 2020s/early 2030s before they can get an engine as good as the RD-170. Their YF-130, while technically very good according to recent tests, is still a bit less efficient. Think about that, a 40 year gap. Aerospace is hard.
Using Russian engines, like the ISS collaboration was an attempt by the US to keep soviet rocket scientists in business in civilian roles so they wouldn't be incentivized to spread around the world proliferating ICBM tech.
In the process the US paid a huge price (decay of domestic design capability) and it's debatable if the goal was achieved.
Edit: Thankfully the decay has been made up for over recent years with the boom in private launch companies and of course, SpaceX's work.
Even CALT, the major launch vehicle provider in China, admits it will be well into the late 2020s/early 2030s before they can get an engine as good as the RD-170. Their YF-130, while technically very good according to recent tests, is still a bit less efficient. Think about that, a 40 year gap. Aerospace is hard.
https://en.wikipedia.org/wiki/RD-170