ACROSTIC POEM W – Weapons like poison gas and tanks were new O - Only the USA refused to sign the Treaty of Versailles R – Russia left the war to try to stop a revolution in their own country L – League of Nations was President Wilson’s idea for preventing another world war D – Death of the Archduke of Austria-Hungry was the spark that started the war in Europe W – Wanting control of more land is called imperialism A – Alliances between nations were a major cause of the war R – Reliance on women workers in American factories was necessary when the men went off to war O – Only after the USA arrived in France did the Allies begin to push back the German invasions in Eueope N – Nationalist feelings that some small countries should be independent also caused the conflict E – Europe’s map looked very different after the war