in 1939 the immediate response of the united states to the start of world war 2 in europe was to
World War II In November 1939, the United States, who were taking measures to assist China and the Western Allies, amended the Neutrality Act to allow "cash and carry" purchases by the Allies.[103] In 1940, following the German capture of Paris, the size of the United States Navy was significantly increased. In September the United States further agreed to a trade of American destroyers for British bases.[104] Still, a large majority of the American public continued to oppose any direct military intervention in the conflict well into 1941.[105]
United States in World War I In 1917, with Russia experiencing political upheaval following widespread disillusionment there over the war, and with Britain and France low on credit, Germany appeared to have the upper hand in Europe,[4] while the Ottoman Empire clung to its possessions in the Middle East. In the same year, Germany 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. Germany 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 Germany on April 6, 1917.[5] On December 7, 1917, the U.S. declared war on Austria-Hungary.[6][7] U.S. troops began arriving on the Western Front in large numbers in 1918.