Worse than that, two NASA astronauts are currently in orbit as part of Expedition 39. Richard Mastracchio is due to re-enter next month, so he's probably ok. But Steven Swanson only launched in March, will transfer to Expedition 40 and is seriously in danger of getting no ride home if the US and Russia really decide to have a pissing match.
I personally think Ukraine will probably split into two nations, but SFW? Cool it, you guys!
NOTE: Other members of Expedition 39 are Japanese Commander Koichi Wakata and Russian engineers Mikhail Tyurin, Aleksandr Skvortsov, and Oleg Artemyev.
Other people are now noticing this potential problem. Dmitry Rogozin, Russia’s deputy prime minister, made a very wry joke in a Russian-language tweet yesterday:
"After analyzing the sanctions against our space industry, I suggest to the USA to bring their astronauts to the International Space Station using a trampoline.”
More detail on that
On Coast-to-Coast AM last night, Bob Zimmerman also warned that Swanson could get stranded, but he said it's literally impossible for the Russians to operate ISS without NASA (I didn't know that). He even hinted at the dire outcome that ISS would have to be abandoned.
My next question is "If Commander Wakata is ordered to prevent Swanson from boarding a Soyuz spacecraft for de-orbiting, would he obey?"
Update 14 May
According to this article in the Daily Telegraph, Russia will refuse to carry US astronauts to ISS after 2020.
Here's the full transcript of yesterday's announcement. It supports the Telegraph's story to the extent that it's clear the Russians will consider ISS a dead duck at the end of 2020. It's not just that they'll refuse to carry Americans -- they won't be launching Russians, either.