— funds that were in large part used to buy munitions, raw materials, and food from across the Atlantic. Until 1917, Wilson made minimal preparations for a land war and kept the United States Army on a small peacetime footing, despite increasing demands for enhanced preparedness. He did, however, expand the United States Navy. In 1917, with the Russian Revolution and widespread disillusionment over the war, and with Britain and France low on credit, the German Empire appeared to have the upper hand in Europe, while the Ottoman Empire clung to its possessions in the Middle East. In the same year, the German Empire decided to resume unrestricted submarine warfare against any vessel approaching British waters; this attempt to starve Britain into surrender was balanced against the knowledge that it would almost certainly bring the United States into the war. The German Empire also made a secret offer to help Mexico regain territories lost in the Mexican–American War in an encoded telegram known as the Zimmermann Telegram, which was intercepted by British Intelligence. Publication of that communique outraged Americans just as German U-boats started sinking American merchant ships in the North Atlantic. Wilson then asked Congress for "a war to end all wars" that would "make the world safe for democracy", and Congress voted to declare war on the German Empire on April 6, 1917. On December 7, 1917, the U.S. declared war on Austria-Hungary. U.S. troops began arriving on the Western Front in large numbers in 1918. Neutrality After the war began in 1914, the United States proclaimed a policy of neutrality despite President Woodrow Wilson's antipathies against the German Empire. When the German U-boat U-20 sank the British liner on 7 May 1915 with 128 U.S. citizens aboard, Wilson demanded an end to German attacks on passenger ships, and warned that the USA would not tolerate unrestricted submarine warfare in violation of "American rights" and of "international and obligations." Wilson's Secretary of State, William Jennings Bryan, resigned, believing that the President's protests against the German use of U-boat attacks conflicted with America's official commitment to neutrality. On the other hand, Wilson came under pressure from war hawks led by former president Theodore Roosevelt, who denounced German acts as "piracy", and from British delegations under Cecil Spring Rice and Sir Edward Grey. U.S. Public opinion reacted with outrage to the suspected German sabotage of Black Tom in Jersey City,