The 1917 United States declaration of war on Austria-Hungary, officially House Joint Resolution 169, was a resolution adopted by the United States Congress declaring that a state of war existed between the United States of America and the Austro-Hungarian Empire. It occurred eight months after the earlier declaration of war against Germany that had brought the United States into World War I. Enacted on December 7, 1917 and coming into effect the same day, it was officially terminated in 1921, three years after the effective capitulation of Austria-Hungary.