Secret treaty
A secret treaty is a treaty between nations that is not revealed to other nations or interested observers. An example would be a secret alliance between two nations to support each other in the event of war. The opposing nations would be unaware of the treaty and therefore unable to add it to their calculations, which could obviously result in a difficult situation for the party that declared war when suddenly confronted with the troops of two or even three nations. Secret treaties were common before the First World War, and many blamed them for helping spark that conflict. Other noted secret treaties include the protocols of the 1939 Molotov–Ribbentrop Pact that divided Eastern Europe and the 1947 Quadripartite Agreement on intelligence matters between the United Kingdom, the United States, Canada, and Australia. Another notable secret treaty was the Hoare–Laval Pact of 1935, however the details of the treaty were leaked to the press, resulting in the resignation of both of the ministers.
At the peace conference following World War I that resulted in the Treaty of Versailles, Woodrow Wilson intended his Fourteen Points to form the basis of the treaty. However, the final treaty was quite different from what he had proposed. One of the points was that no secret treaties should be made and, to ensure this, that all of these treaties should be made through the League of Nations. Although the final version of the Versailles treaty did not contain this provision, Article 18 of the Covenant of the League of Nations provided that "[e]very treaty or international engagement entered into hereafter by any Member of the League shall be forthwith registered with the Secretariat and shall as soon as possible be published by it. No such treaty or international engagement shall be binding until so registered." When Germany and the Soviet Union entered into the Molotov–Ribbentrop Pact, neither was a member of the League of Nations.