French divisions might have to be diverted to aid in the defense
of the new Piave front. General Byng's break of the German lines at
Cambrai was more than offset by the equally brilliant German
counter-attack. And every day the submarine was taking its toll of Allied
shipping.

Following the Italian debacle, the Bolshevik revolution of November
indicated that Russia would wholly withdraw and that that great potential
source of man-power for the Allies could no longer be counted upon.
Allied leaders realized that Germany would be able to transfer large
numbers of troops to the western front, and became seriously alarmed.
"The Allies are very weak," cabled General Pershing, on the 2d of
December, "and we must come to their relief this year, 1918. The year
after may be too late. It is very doubtful if they can hold on until 1919
unless we give them a lot of support this year." Showing that the
schedule of troop shipments would be inadequate and complaining that the
actual shipments were not even being kept up to programme, Pershing
insisted upon the importance of the most strenuous efforts to secure
extra tonnage, which alone would make it possible for the American army
to take a proper share in the military operations of 1918.

The serious representations of General Pershing were reinforced by
Colonel House when he returned from abroad on the 15th of December. For
six weeks he had been in conference, as head of a war mission, with the
Allied political and military leaders, who now realized the necessity of
unity of plan. Because of his personal intimacy with French and British
statesmen and his acknowledged skill in negotiations, House had done
much to bring about Allied harmony and to pave the way for a supreme
military command. Like Pershing, he was convinced of the danger
threatening the Allies, and from the moment of his return began the
speeding-up process, which was to result in the presence of a large
American force on the battle front at the moment of crisis in the early
summer of 1918.

Tonnage was obviously the vital factor upon which effective military
assistance depended. The United States had the men, although they were
not completely trained, but the apparent impossibility of transporting
them formed the great obstacle. The problem could not have been solved
without the assistance of the Allies. With the threat of the German
drive, and especially after the first German victories of 1918, they
began to ap