In the aftermath of World War I, the defeated German Empire was made to sign the Treaty of Versailles. This restricted German military and territorial growth and required the payment of massive war reparations. Civil war in Russia led to the creation of the communist Soviet Union which soon fell under the control of Joseph Stalin. In Italy, Benito Mussolini seized power as a fascist dictator promising to create a “New Roman Empire”. The ruling Kuomintang party in China launched a unification campaign against rebelling warlords in the mid-1920s, but was soon embroiled in a civil war against its former Chinese communist allies. In 1931, an increasingly militaristic Japanese Empire, which had long sought influence in China as the first step of its right to rule Asia, used the Mukden Incident as justification to invade Manchuria; the two nations then fought several small conflicts until the Tanggu Truce in 1933.
German troops at the 1935 Nuremberg Rally
In 1933, National Socialist Adolf Hitler became the leader of Germany and began a massive rearming campaign. This worried France and the United Kingdom, who had lost much in the previous war, as well as Italy, which saw its territorial ambitions threatened by those of Germany. To secure its alliance, the French allowed Italy a free hand in Ethiopia, which Italy desired to conquer. The situation was aggravated in early 1935 when the Saarland was legally reunited with Germany and Hitler repudiated the Treaty of Versailles, speeding up remilitarization and introducing conscription. Hoping to contain Germany, the United Kingdom, France and Italy formed the Stresa Front. The Soviet Union, also concerned due to Germany’s goals of capturing vast areas of eastern Europe, concluded a treaty of mutual assistance with France.
These alliances did not amount to much. The Franco-Soviet pact, required to go through the League of Nations bureaucracy before taking effect, was essentially toothless and in June of 1935, the United Kingdom made an independent naval agreement with Germany easing prior restrictions. The isolationist United States, concerned with events in Europe and Asia, passed the Neutrality Act in August. In October Italy invaded Ethiopia, but was soon politically isolated, with Germany the only major European nation supporting its aggression. Alliances shifted, with Italy revoking its objections to Germany’s goal of making Austria a satellite state.
In March of 1936, Hitler remilitarized the Rhineland in direct violation of the Versailles and Locarno treaties, receiving little response from other European powers. When the Spanish Civil War broke out in July, Hitler and Mussolini supported fascist Generalísimo Francisco Franco in his civil war against the Soviet-supported Spanish Republic. Both sides used the conflict to test new weapons and methods of warfare.
With tensions mounting, efforts to strengthen or consolidate power were made. In October, Germany and Italy formed the Rome-Berlin Axis and a month later Germany and Japan, each believing communism–and the Soviet Union in particular–to be a threat, signed the Anti-Comintern Pact, which Italy would join in the following year. In China, the Kuomintang and communist forces agreed on a ceasefire to present a united front to oppose Japan.