Over the weekend, Ukraine’s military stunned the world. After months of a kind of stalemate, its military took hundreds of miles of territory back from Russia — its biggest victory since the start of the war.How did the war reach this critical point, and what does Ukraine’s success mean for the future?Guest: Eric Schmitt, a correspondent covering national security for The New York Times.Background reading: A lightning Ukrainian offensive in the country’s northeast has reshaped what had become a grinding war of attrition.Stunned by a lightning advance, Russia has acknowledged the loss of the northern region of Kharkiv, which cast doubt on the premise that Ukraine could never defeat it. For more information on today’s episode, visit nytimes.com/thedaily. Transcripts of each episode will be made available by the next workday.