In the end, the year brought conclusive victories to neither side. The Allies were shaken and exhausted, and Russia's imminent departure from the war meant the end of the eastern front. Nonetheless, America's mobilization of its vast strength and its commitment to send a massive army to Europe rebalanced the scales. Moreover, the war against the U-boat had been contained, albeit not completely defeated. The Allies still seemed the stronger side. But Great Britain and France had to hold on in the face of a final German offensive. Victory in the east offered Germany the opening to concentrate the bulk of its armies in France. Driven close to the limit of human and material resources, the German leaders could still spend them on a final attack in the west.