and the US $17 billion; among the Central Powers Germany spent $20 billion. Aftermath In the aftermath of the war, four empires disappeared: the German, Austro-Hungarian, Ottoman, and Russian. Numerous nations regained their former independence, and new ones were created. Four dynasties, together with their ancillary aristocracies, fell as a result of the war: the Romanovs, the Hohenzollerns, the Habsburgs, and the Ottomans. Belgium and Serbia were badly damaged, as was France, with 1.4 million soldiers dead, not counting other casualties. Germany and Russia were similarly affected. Formal end of the war A formal state of war between the two sides persisted for another seven months, until the signing of the Treaty of Versailles with Germany on 28 June 1919. The United States Senate did not ratify the treaty despite public support for it, and did not formally end its involvement in the war until the Knox–Porter Resolution was signed on 2July 1921 by President Warren G. Harding. For the United Kingdom and the British Empire, the state of war ceased under the provisions of the Termination of the Present War (Definition) Act 1918 with respect to: Germany on 10 January 1920. Austria on 16 July 1920. Bulgaria on 9 August 1920. Hungary on 26 July 1921. Turkey on 6 August 1924. After the Treaty of Versailles, treaties with Austria, Hungary, Bulgaria, and the Ottoman Empire were signed. The Ottoman Empire disintegrated, with much of its Levant territory awarded to various Allied powers as protectorates. The Turkish core in Anatolia was reorganised as the Republic of Turkey. The Ottoman Empire was to be partitioned by the Treaty of Sèvres of 1920. This treaty was never ratified by the Sultan and was rejected by the Turkish National Movement, leading to the victorious Turkish War of Independence and the much less stringent 1923 Treaty of Lausanne. Some war memorials date the end of the war as being when the Versailles Treaty was signed in 1919, which was when many of the troops serving abroad finally returned home; by contrast, most commemorations of the war's end concentrate on the armistice of 11 November 1918. Legally, the formal peace treaties were not complete until the last, the Treaty of Lausanne, was signed. Under its terms, the Allied forces left Constantinople on 23 August 1923. Peace treaties and national boundaries After the war, there grew a certain amount of academic focus on the causes of