At the moment, according to news reports, Russia will use the naval base in Sevastopol for Soyuz survival training. Will US astronauts be expected to train there? I hope not, and if NASA does not understand this then Congress should forbid it (assuming current laws do not already cover this).
While one could argue the naval base was leased Russian property before the occupation, Putin's recent decision (and you can be certain nothing happens without his approval) is ill-timed and insulting to Ukrainians. It is one more example that Russia has gone off course and is willing to further jeopardize its reduced standing in the world for cheap political showmanship.