Open this photo in gallery:Ukraine's President Volodymyr during a welcoming ceremony in front of the Palace of Serbia, in August.ANDREJ ISAKOVIC/AFP/Getty ImagesSave for laterA word often applied to Volodymyr Zelensky by foreign leaders and commentators is “Churchillian.”They’re referring, accurately, to the Ukrainian President’s ability to rally his people around acts of heartbreaking sacrifice, to marshal an international coalition to arm and support his country, and to embrace innovative technologies that have transformed the way the world arms itself.But there’s another meaning of “Churchillian” that’s also applied to Mr. Zelensky, mainly at home.Winston Churchill was a disastrously bad domestic leader. In...