Answer:
1. The Lusitania
2. The German invasion of Belgium
3. American loans
4. The reintroduction of unrestricted submarine warfare
1. The Lusitania
In early 1915, Germany introduced a policy of unrestricted submarine warfare in the Atlantic. This meant U-Boats were hunting and sinking merchant shipping without warning. The RMS Lusitania left New York on 1st May, 1915, bound for Liverpool. On 7th May it was spotted off the coast of Ireland by U-20 and torpedoed. Of 1,962 passengers, 1,198 lost their lives. Among the dead were 128 Americans, causing widespread outrage in the US.
2. The German invasion of Belgium
Following Germany’s invasion of neutral Belgium in 1914, stories began to circulate about atrocities committed against Belgian civilians. These stories, both true and exaggerated, were seized upon for propaganda. So-called “atrocity propaganda” spread far and wide, painting the Germans as a barbaric nation bent on ruthless, indiscriminate destruction. This propaganda was soon sweeping the US, firing anti-German sentiment.
3. American loans
The US had a vested financial interest in the outcome of the war in Europe. American businesses and banks made huge loans to the Allies. If they didn’t win then they were unlikely to get their money back.
4. The reintroduction of unrestricted submarine warfare
Germany resumed unrestricted submarine warfare in 1917. Knowing they risked provoking the United States into joining the war, Germany gambled on defeating the British before the US had a chance to mobilise. During February and March, several US cargo vessels were sunk without warning, resulting in the United States severing diplomatic ties with Berlin.
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