“One day,” Volodymyr Zelenskiy told the UN general assembly in September 2019, “I would like this speech to be known as the 15 minutes that changed the world.” It’s quite a standard to set. You can’t say that if you are on just after lunch at the Investors’ Chronicle conference on pension reform. But this is war and war changes what rhetoric can do. Hopes of a better world are elevated from platitudes. In this short and compelling collection, Zelenskiy is the first social media orator to enter the pantheon of war speakers. Ukraine’s president travels the world by video...