A remarkable thing has happened on the world’s battlefields. Ukraine — a nation that was supposed to dissolve within days of a Russian invasion — has fought Russia to a stalemate, revolutionizing land warfare in the process. It has become an indispensable security partner in the Western alliance, including in the war against Iran.Now, Volodymyr Zelenskyy, Ukraine’s president, is taking the next step, one that would have been unthinkable even as recently as 2024. By word and deed, he’s showing Europe and the world how the post-American free world can preserve its liberty and independence. This is what happens when,…