As a matter of fact, in spite of British efforts, there had been an immense increase of indirect trade with Germany through neutrals. While American exports to Germany in 1915 were $154,000,000 less than in 1913, and in fact practically ceased altogether, American exports to Holland and the Scandinavian states increased by $158,000,000. This trade continued up to the time when the United States entered the war, after which all the restrictions which England had employed were given a sharper application. By a simple process of substitution, European neutrals had been able to import commodities for home use, and export their own products to Germany. Now, in order to secure supplies at all, they were forced to sign agreements which put them on rations and gave the Western Powers complete control of their exports to Germany. The effect of the Allied blockade upon Germany is suggested by the accompanying chart. In the later stages of the war it created a dearth of important raw materials, crippled war industries, brought the country to the verge of starvation, and caused a marked lowering of national efficiency and morale. Germany protested vigorously to the United States for allowing her foodstuffs to be shut out of Germany while at the same time shipping to England vast quantities of munitions. Throughout the controversy, however, Great Britain profited by the fact that while her methods caused only financial injury to neutrals, those employed by Germany destroyed or imperiled human lives. _The Submarine Campaign_ [Illustration: From _The Blockade of Germany_, Alonzo E. Taylor, WORLD'S WORK, Oct. 1919. EFFECTS OF THE BLOCKADE OF GERMANY Decreased supply of commodities in successive years of the war.] The German submarine campaign may be dated from February 18, 1915, when Germany, citing as a precedent Great Britain's establishment of a military area in the North Sea, proclaimed a _war zone_ "in the waters around Great Britain and Ireland, including the whole English Channel," within which enemy merchant vessels would be sunk without assurance of safety to passengers or crew. Furthermore, as a means of keeping neutrals out of British waters, Germany declared she would assume no responsibility for destruction of neutral ships within this zone. What this meant was to all intents and purposes a "paper" submarine blockade of the British Isles. Its illegitimacy arose from the fact that it was conducted surreptitiously over a vast area, and was only in the slightest degree effective, causing a destruction each month of less than one percent of the traffic. Had it been restricted to narrow limits, it would have been still less effective, owing to the facility of countermeasures in a small area.