President Volodymyr Zelensky of Ukraine and other leaders are calling for NATO to impose a no-fly zone over the country, but thus far, NATO leaders haven't signaled they're willing to make that move yet, fearing it could be seen as a direct act of war against Russia and risk escalating the conflict. 

For more, KCBS Radio news anchor Lisa Chan spoke with Don Jensen, Director of Russia and Europe at the U.S. Institute of Peace and former diplomat at the U.S. Embassy in Moscow