Photo by Evelyn Hockstein / Reuters Hours after Vladimir Putin’s state of the nation speech in Moscow on 21 February, the US president Joe Biden delivered his own remarks in Warsaw, Poland. Twenty-four hours earlier, he had secretly travelled to Kyiv to meet Volodymyr Zelensky, where the two leaders strolled through the city centre as the air-raid sirens wailed. The next day, standing in front of the Royal Castle in the Polish capital, which was lit up in the blue and gold colours of the Ukrainian flag, Biden reflected on how Zelensky, and his nation, had defied the world’s expectations...