For 1461 days, Ukraine has been defending itself against Russia's full-scale invasion, initiated four years ago by Kremlin leader Vladimir Putin. While Ukraine's continued resistance into the fifth year of the conflict is certain, the crucial question remains whether its resources will be sufficient to sustain an effective defense against the aggressor. The ongoing struggle highlights the precarious balance of Ukraine's ability to maintain its territorial integrity and sovereignty against a determined adversary, with the longevity of its defense capabilities being a primary concern.