Nevertheless, no enthusiasm was too extravagant when at last America abandoned her neutrality--and abandoned it on the unidealistic ground of material self-protection. By the autumn of 1916 the allies had reached their low-water mark. The summer campaign on the Somme had cost more than half a million casualties without breaking the German line; the Russian thrust in the south had been repelled and the Russian armies flung back with such violence that they required long leisure for recovery and re-equipment, if indeed they were ever again to play an effective part in the war; Servia, left to the undivided attention of Austria, had been put out of action; and Roumania, entering the war precipitously, was now almost expunged from the map of Europe; if the French had succeeded at Verdun, they had failed everywhere else; forgetting everything and learning nothing from the tragedy of the Dardanelles, the British government had been persuaded by the French to lock up another army in Salonica; the battle of Jutland was still widely believed to have been the greatest defeat in British naval history; Ireland was smouldering with a half-extinguished half-revolution; and a wave of "defeatism" was spreading through England and France until even the armies were affected. When the belligerents took stock before settling down to the trench-warfare winter campaign of 1916-17, all must have felt that the war had reached its climax. The general exhaustion was so great that, even if hostilities had ceased, every country would have been crippled; if hostilities continued, they would continue on a scale of unlimited effort in which no reserve of strength would any longer be husbanded. Set free on her eastern frontier, Germany must mass all her resources in one last effort to break through the western line; the allies must hold out till the attempt had spent itself and then strike one last blow at a worn enemy; Germany must in turn prevent the allies from holding out by cutting their sea-communications. If unrestricted submarine warfare ranged America on the side of the allies, it must have been felt that either the war would be over before any effective help could be given or else that, in the final, hopeless, death-grapple, a few million soldiers more or less would not substantially change the degree or character of Germany's defeat.