On January 13, 1935, a plebiscite conducted in the Saar region showed that 90% of residents desired to be reintegrated with Nazi Germany. The League of Nations, which had been mandated by the 1919 Treaty of Versailles to administer the Saar for 15 years, returned the territory to Germany following the plebiscite.
(Taken from Wars of the 20th Century – World War II in Europe)
Post-World War I Pacifism Because World War I had caused considerable toll on lives and brought enormous political, economic, and social troubles, a genuine desire for lasting peace prevailed in post-war Europe, and it was hoped that the last war would be “the war that ended all wars”. By the mid-1920s, most European countries, especially in the West, had completed reconstruction and were on the road to prosperity, and pursued a policy of openness and collective security. This pacifism led to the formation in January 1920 of the League of Nations (LN), an international organization which had membership of most of the countries existing at that time, including most major Western Powers (excluding the United States). The League had the following aims: to maintain world peace through collective security, encourage general disarmament, and mediate and arbitrate disputes between member states. In the pacifism of the 1920s, the League resolved a number of conflicts (and had some failures as well), and by mid-decade, the major powers sought the League as a forum to engage in diplomacy, arbitration, and disarmament.
In September 1926, Germany ended its diplomatic near-isolation with its admittance to the League of Nations. This came about with the signing in December 1926 of the Locarno Treaties (in Locarno, Switzerland), which settled the common borders of Germany, France, and Belgium. These countries pledged not to attack each other, with a guarantee made by Britain and Italy to come to the aid of a party that was attacked by the other. Future disputes were to be resolved through arbitration. The Locarno Treaties also dealt with Germany’s eastern frontier with Poland and Czechoslovakia, and although their common borders were not fixed, the parties agreed that future disputes would be settled through arbitration. The Treaties were seen as a high point in international diplomacy, and ushered in a climate of peace in Western Europe for the rest of the 1920s. A popular optimism, called “the spirit of Locarno”, gave hope that all future disputes could be settled through peaceful means.
In June 1930, the last French troops withdrew from the Rhineland, ending the Allied occupation five years earlier than the original fifteen-year schedule. And in March 1935, the League of Nations returned the Saar region to Germany following a referendum where over 90% of Saar residents voted to be reintegrated with Germany.
In August 1938, at the urging of the United States and France, the Kellogg-Briand Pact (officially titled “General Treaty for Renunciation of War as an Instrument of National Policy”) was signed, which encouraged all countries to renounce war and implement a pacifist foreign policy. Within a year, 62 countries signed the Pact, including Britain, Germany, Italy, Japan, the Soviet Union, and China. In February 1929, the Soviet Union, a signatory and keen advocate of the Pact, initiated a similar agreement, called the Litvinov Protocol, with its Eastern European neighbors, which emphasized the immediate implementation of the Kellogg-Briand Pact among themselves. Pacifism in the interwar period also manifested in the collective efforts by the major powers to limit their weapons. In February 1922, the five naval powers: United States, Britain, France, Italy, and Japan signed the Washington Naval Treaty, which restricted construction of the larger classes of warships. In April 1930, these countries signed the London Naval Treaty, which modified a number of clauses in the Washington treaty but also regulated naval construction. A further attempt at naval regulation was made in March 1936, which was signed only by the United States, Britain, and France, since by this time, the previous other signatories, Italy and Japan, were pursuing expansionist policies that required greater naval power.
An effort by the League of Nations and non-League member United States to achieve general disarmament in the international community led to the World Disarmament Conference in Geneva in 1932-1934, attended by sixty countries. The talks bogged down from a number of issues, the most dominant relating to the disagreement between Germany and France, with the Germans insisting on being allowed weapons equality with the great powers (or that they disarm to the level of the Treaty of Versailles, i.e. to Germany’s current military strength), and the French resisting increased German power for fear of a resurgent Germany and a repeat of World War I, which had caused heavy French losses. Germany, now led by Adolf Hitler (starting in January 1933), pulled out of the World Disarmament Conference, and in October 1933, withdrew from the League of Nations. The Geneva disarmament conference thus ended in failure.