I am curious as to how you would remove us from the ISS. A third of the pressurized modules on the ISS are Russian [1]. Do we just take them with us when we leave? How do we achieve that?
The ISS is made up of 16 pressurized modules: five Russian modules ( Zarya, Pirs, Zvezda, Poisk and Rassvet), eight US modules (BEAM, Leonardo, Harmony, Quest, Tranquility, Unity, Cupola, and Destiny), two Japanese modules (the JEM-ELM-PS and JEM-PM) and one European module (Columbus).
Removing the Russian segment from the ISS isn't feasible, as it has the only module capable of GNC, and Progress is the only currently flying craft that can raise the ISS's orbit (which, being in LEO, slowly decays).
Russians also can't remove Zarya anyway because they don't own it. The US purchased the module decades ago when Russians had no money. (They still have no money, but they used to have no money, too.)
I suppose in theory the US could just starve Roscosmos of funding by cutting back on implicit subsidies. That would require having a contingency in place to keep the station viable without Russian involvement. The problem is that would be massively expensive. As you say, that’s a third of the station. In practice you’re quite right, that plan is completely unviable.
If it were reasonably easy to just replace the existing modules, they coukd have been replaced.
But if you want these specific modules, already integrated into the station, which are an opposite of a commodity, the price includes a significant premium.
[1] https://en.wikipedia.org/wiki/Assembly_of_the_International_...
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The ISS is made up of 16 pressurized modules: five Russian modules ( Zarya, Pirs, Zvezda, Poisk and Rassvet), eight US modules (BEAM, Leonardo, Harmony, Quest, Tranquility, Unity, Cupola, and Destiny), two Japanese modules (the JEM-ELM-PS and JEM-PM) and one European module (Columbus).
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*Pirs was undocked to make place for Nauka.