As the Russian winter offensive reaches its culmination, Ukraine is poised to seize the initiative. In the coming weeks, it plans to conduct an offensive operation, or series of offensives, that may prove decisive in this phase of the conflict. This is not Ukraine’s only remaining opportunity to liberate a substantial amount of territory and inflict a major defeat on Russian forces, but the upcoming offensive may be the moment when available Western military equipment, training, and ammunition best intersect with the forces set aside by Ukraine for this operation. Ukraine is also eager to demonstrate that, despite months of brutal fighting, its military is not exhausted and remains able to break through Russian lines.