In his Twitter account the Deputy Prime Minister of Russia Dmitry Rogozin has stated “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.” Last month when talking about U.S. economic sanctions against Russia he told journalists in the Crimean city of Simferopol”….”They don’t understand that the sanctions will hit them like a boomerang.”
Although the U.S. does have written agreements with Russia which pay for them to launch U.S. astronauts the current crisis could make those agreements worthless. There has, as of yet, not been any formal statement or notification that Russia will not launch astronauts any longer. This could all amount to nothing more than bluster but on the other hand it could be real. The U.S. has not had the capability to send men into space since the space shuttle retired. They became totally reliant on Russian until the replacement rockets and crew vehicles are ready for use.
The current astronauts are in no danger as there is always a return vehicle attached to the space station ready to return them to Earth on a moments notice. Future launches are however in jeopardy.