Why U.S. Soldiers Won’t Come to Ukraine’s Rescue

Since the beginning of the standoff with Moscow over Ukraine, President Biden has been clear that he will not allow American troops to come into direct combat with Russians. Why has the U.S., a country that has intervened all over the world in various contexts, taken that powerful option off the table? Guest: David E. Sanger, a White House and national security correspondent for The New York Times.