He told U.S. lawmakers that he had a dream, invoking the Rev. Martin Luther King Jr. to describe Ukraine’s fight against the Russian invasion. He said to the British Parliament that his country would fight until the end, in forests and fields, a vow resonant of Winston Churchill’s exhortations against Nazism. To members of the German Parliament he spoke of a new wall dividing Europe, echoing the Berlin Wall of the Cold War.

The passionate speeches, delivered remotely by Ukrainian President Volodymyr Zelenskyy in his now-ubiquitous military-issue shirt, are part of a vigorous rhetorical effort to rally international support — for arms, or aid to his country, or sanctions against Russia.

Zelenskyy, a former comedian who ran a populist campaign to become president in 2019, is no stranger to performing, and his social-media missives and speeches have transformed him into a global symbol of his country’s resistance to Russian aggression.