Ukrainian President Volodymr Zelenskyy asked Congress for further help standing up to Russia, and repeated his call for a no-fly zone over Ukraine. The speech shows the U.S. needs to support Ukrainian resistance, but also diplomacy that can end the conflict without U.S. forces getting involved, says Marcus Stanley from the Quincy Institute for Responsible Statecraft.

Ukrainian President Volodymr Zelenskyy has called on the U.S. and NATO allies to establish a no-fly zone over Ukraine to prevent Russian aircraft from attacking. But establishing a no-fly zone requires much more than just making a statement — military aircraft would have to patrol the skies and be ready to fire at any Russian planes that cross into the...