Russians and rockets

 One reads where Putin has decided to stop selling rocket engines to the US (and presumably stop sponsoring launches of US satellites from Krasnoyarsk). A decade ago, when NASA was in serious neglect due to the depredations of the Bush years, this would've really mattered to America's space enterprise. But today, apart from the International Space Station, our country has very little cooperation with Russia in this arena anyway. Elon Musk, whose company SpaceX supplies space vehicles capable of supplying and even, in an emergency, evacuating, the ISS, was contemptuous of the announcement (predictably). But I admit I was caused to wonder for the first time, what about the ISS? There are Russian and American astronauts up there. Must be a very tense situation.