Of the many provisions in the treaty, one of the most important and controversial required "Germany accept the responsibility of Germany and her allies for causing all the loss and damage" during the war (the other members of the Central Powers signed treaties containing similar articles). This article, Article 231, later became known as the War Guilt clause. The treaty forced Germany to disarm, make substantial territorial concessions, and pay reparations to certain countries that had formed the Entente powers. In 1921 the total cost of these reparations was assessed at 132 billion marks (then $31.4 billion or £6.6 billion, roughly equivalent to US $442 billion or UK £284 billion in 2018). At the time economists, notably John Maynard Keynes (a British delegate to the Paris Peace Conference), predicted that the treaty was too harsh—a "Carthaginian peace"—and said the reparations figure was excessive and counter-productive, views that, since then, have been the subject of ongoing debate by historians and economists from several countries. On the other hand, prominent figures on the Allied side such as French Marshal Ferdinand Foch criticized the treaty for treating Germany too leniently.
The result of these competing and sometimes conflicting goals among the victors was a compromise that left no one content: Germany was neither pacified nor conciliated, nor was it permanently weakened. The problems that arose from the treaty would lead to the Locarno Treaties, which improved relations between Germany and the other European powers, and the re-negotiation of the reparation system resulting in the Dawes Plan, the Young Plan, and the indefinite postponement of reparations at the Lausanne Conference of 1932.
Although it is often referred to as the "Versailles Conference", only the actual signing of the treaty took place at the historic palace. Most of the negotiations were in Paris, with the "Big Four" meetings taking place generally at the Quai d'Orsay.
The First World War (1914–1918) was fought across Europe, the Middle East, Africa and Asia. Countries beyond the war zones were also affected by the disruption of international trade, finance and diplomatic pressures from the belligerents. In 1917, two revolutions occurred within the Russian Empire, which led to the collapse of the Imperial Government and the rise of the Bolshevik Party led by Vladimir Lenin.
On 6 April 1917, the United States entered the war against the Central Powers due to German submarine warfare against merchant ships trading with France and Britain, which led to the sinking of the RMS Lusitania and the loss of 128 American lives, as well as the interception of the Zimmerman Telegram, sent by the Empire of Germany to Mexico, urging for a declaration of war against the United States. The American war aim was to detach the war from nationalistic disputes and ambitions after the Bolshevik disclosure of secret treaties between the Allies. The existence of these treaties tended to discredit Allied claims that Germany was the sole power with aggressive ambitions.