What if Russia Refuses to Shuttle American Astronauts Back to Earth?

The US pays Russia to take astronauts into space. With the crisis in Ukraine, what if Russia decided not to bring Americans on the Space Station back to Earth?
3/9/2014
Updated:
7/18/2015

Since NASA discontinued the Space Shuttle program, the United States pays Russia $70 million per head to take American astronauts into space. There’s a landing scheduled for March 10 and a launch scheduled for March 25. 

With the crisis in Ukraine causing tension between the United States and Russia, what happens if Russia decided that they don’t want to bring American astronauts on the International Space Station back to Earth. Are they stranded? What are the options for brining them back?