Yep, that's exactly why the US got Russia into the ISS; more russian space scientists working on ISS meant no Russian brains and effort spent in russian arms and weapons programs.
Not exactly. The Russians were not in good shape at the fall of the Soviet Union. A lot of their engineers were going unpaid: there was a massive shift of them into the US and other places. The United States was especially worried about this with respect to aerospace technologies. Could North Korea? Iran? Yes, even China, snaffle up engineers like the US and SU did with Germans? Or like the US did when Canada cancelled the Arrow? What would happen when all those engineers and scientists went flooding out into the world?
At the same time, the US was trying to decide between Space Station Freedom and the Superconducting Super Collider. The Clinton Administration had declared there was only money for one. The head of NASA at the time came forward with the plan to pay the Russians for their knowledge in aerospace and keep the Russian engineers in Russia. This won over the administration as it kept a vital and restricted set of technologies from spreading to the rest of the world.
The first step was renting the Mir space station. The second was paying the Russians for the Zarya module: the Russians built it, but the US paid for and owns it. The space station's orbit was even adjusted so it would be easier for the Russians to reach it. The US agreed to have the Russians be equal partners, despite the Russians paying a fraction of the money into the project. The US has spent around $60B vs Russia spending $12B.
Russia during the 90s was in no position, financially, to develop new weapons. $12B is a very, very small amount over the 20 years and, if anything, has preserved know-how for the Russians they would have lost. If there were ways the US screwed over the Russians, it was not through this. That's another topic for another thread.
That said, the Russians having the capabilities they had preserved allows them to participate in the Chinese space station if China so will's it. It would not be a bad move on China's part, so long as it is made clear the Russians are very much junior partners in the endeavor. That may be what happened since the head of Rogozin stated recently Russia would be more interested in building its own national space station than participating in others'. The Russians, in no small part, pulled out of the Gateway Station program since the US this time was running it as an American program rather than a fully joint one with the Russians being full peers like in the ISS.
I, personally, hope the Russians do participate in the Chines station. Having more than one access route to the ISS turned out to be a wonderful thing. Russia could provide the backup route for the Chinese should something go terribly wrong. Eventually, China will have this capability internally. When it does, the Russians would still be a useful backup, but less necessary. Finally, for all the headaches the Russians could and would bring, they have a unique perspective and have some very bright engineers and scientists and would be a net gain for anyone who can collaborate with them. America or China. Since the bridges have been burned (again) between the US and Russia, that means China. If they want to. Time will tell.