In 1919 the Paris Peace Conference was called to officially negotiate the terms for the end of World War I. While dozens of countries sent ambassadors, the "Big Four" led the conference and were central in negotiating the terms that would eventually be written into the Treaty of Versailles. The Big Four consisted of US President Woodrow Wilson, British Prime Minister David Lloyd George, French Prime Minister Georges Clemenceau, and Italian Prime Minister Vittorio Orlando. In general the purpose of the conference was to establish the peace terms to end the war and form a new postwar world. Leaders at the conference also wanted to ensure that another world war of this scale, magnitude, and destruction would never again occur. In his Fourteen Points, an outline for the postwar world, Woodrow Wilson proposed a League of Nations that would arbitrate disputes between nations and serve as an international peacekeeping agency, much like today's United Nations. Despite being Wilson's idea, the US never joined the League of Nations. In addition to assuring postwar peace, Great Britain, France, and Italy wanted to punish Germany for, in their view, starting the war. They demanded not only reparations in the form of payments for the destruction caused by the war, but also military disarmament of Germany to weaken the country and prevent aggression. They also each had territorial ambitions. Britain and France coveted land in the oil-rich Middle East, and they also wanted to deprive Germany of its colonies and form new buffer states in Europe to further protect against German power.
In order to address these territorial ambitions, Article 22 of the Covenant of the League of Nations formed a mandate system that distributed former territories and colonies among the major powers, allowing them to oversee and essentially control the territories until they were deemed "fit" to govern themselves. Wilson opposed mandates for the US and instead wanted the League of Nations as a whole to administer former German colonies until they were ready for self-government. However, he was outnumbered by the other powers. Under the mandate system, Iraq and Palestine were assigned to Great Britain, while Syria and Lebanon were assigned to France. The resource rich region of Alsace-Lorraine was also taken from Germany and awarded to France.
In addition to losing much of its territory, Germany was forced to pay $32 billion in reparations and to accept all responsibility for the war. Germany was also required to reduce the size of its army and navy. Japan and Italy were also slighted in the treaty negotiations. Japan demanded a racial equity clause and equal standing in the League of Nations, both of which demands were rejected. Japan did, however, gain territory in China, leaving many Chinese angry. At the start of the war, Italy had been promised the Adriatic Coast; however, after the war this region was instead formed into a new country, Yugoslavia. The conditions of the Treaty of Versailles, especially those imposed on Germany, led to increasing political and territorial conflict in the 1920s and 1930s, eventually leading to the outbreak of World War II.