Spring is arriving, a season pregnant with hope and life. But in Ukraine, it has become a harbinger of death and destruction. As battlefield conditions improve, commanders in Moscow and Kyiv prepare for more months of brutal warfare. The signs are that Russian forces are readying a new offensive in eastern Donetsk, where Ukraine still holds around a fifth of the territory that the Kremlin covets but has so far been unable to seize. External factors are aligning in Moscow’s favor, creating the Kremlin’s most advantageous moment in years. Russian President Vladimir Putin looks poised to press his military advantage. This could be a now?or?never chance to shift the war's trajectory decisively for Putin, and produce an outcome that has eluded him for more than four years. Washington’s War...