USSR, yes. But the ISS was launching during a time when USSR no longer existed and Russia was fairly isolated. Hence, "obviously": US at that time had many close allies, but Russia had only a few, and not as technologically advanced.
Quite the opposite, the West welcomed weak and crumbling Russia. To a limited extend, of course, but still Russia joined G7 and many European organizations. Western companies were busy buying privatized Soviet assets pennies on the dollar.
Why obviously?
The USSR invited cosmonauts from all over the world to fly and work at the Salut-6, Salit-7 and Mir stations.[0]
That's France, Britain, Austria, Japan, India, Soviet block countries, Mongolia, Vietnam, Syria and Afghanistan.
[0] https://en.wikipedia.org/wiki/Interkosmos