If the anonymous voices quoted by U.S. news outlets in recent months are any indication, many Western military experts think that they know how to fight Ukraine’s war better than the Ukrainians do. American officials, NBC News reported last month, have “privately expressed disappointment” about how Ukraine had deployed its soldiers and believe that Kyiv’s forces “have not necessarily applied the training principles they received” from NATO militaries. Yet despite such scolding, the Ukrainians keep conducting their war their way. Despite exhortations to gather more forces in the south and try to cut through Russian lines, even if that means exposing more soldiers to enemy air attacks, Ukrainian forces—stymied by minefields—have proceeded more cautiously, conserving personnel in what could be a protracted conflict with a far more populous nation. They have opted instead to attack, using homegrown weapons systems as well as those provided by allies, Russian supply chains and command-and-control facilities deep behind the front line while also focusing on destroying artillery closer to the fighting. Ukrainian commanders believe they understand the fundamental dynamics …