When Russia’s full-scale invasion of Ukraine surpassed 1,418 days last month, it officially exceeded a historic milestone — the same span of time it took Moscow to defeat Nazi Germany in World War II. And unlike the Red Army that pushed all the way to Berlin eight decades ago in what it called the Great Patriotic War, Russia’s 4-year-old, all-out invasion of its neighbor is still struggling to fully capture Ukraine’s eastern industrial heartland. After Moscow failed to seize the capital of Kyiv and install a puppet government in February 2022, the conflict turned into trench warfare with tremendous cost....