World War Ii

World War II, or the Second World War,[1] was a global military conflict, the joining of what had initially been two separate conflicts. The first began in Asia in 1937 as the Second Sino-Japanese War; the other began in Europe in 1939 with the German invasion of Poland.

This global conflict split the majority of the world's nations into two opposing military alliances: the Allies and the Axis powers. It involved the mobilization of over 100 million military personnel, making it the most widespread war in history, and placed the participants in a state of "total war", erasing the distinction between civil and military resources. This resulted in the complete activation of a nation's economic, industrial, and scientific capabilities for the purposes of the war effort. Over 60 million people, the majority of them civilians, were killed, making it the deadliest conflict in human history.[2] The financial cost of the war is estimated at about a trillion 1944 U.S. dollars worldwide,[3][4] making it the most costly war in capital as well as lives.

The Allies were victorious, and, as a result, the Soviet Union and the United States emerged as the world's leading superpowers. This set the stage for the Cold War, which lasted for the next 45 years. The United Nations was formed in hopes of preventing another such conflict. The self determination spawned by the war accelerated decolonization movements in Asia and Africa, while Europe itself began moving toward integration.[5]

In the aftermath of World War I, the defeated German Empire signed the Treaty of Versailles.[6] 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 was under the control of Joseph Stalin. In Italy, Benito Mussolini seized power as a fascist dictator promising to create a "New Roman Empire".[7] The ruling Kuomintang (KMT) 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[8] 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 RallyIn 1933, National Socialist Adolf Hitler became the leader of Germany and began a massive rearming campaign.[9] 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.[10] 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[11][12] 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.[13] 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.[14]

In March of 1936, Hitler remilitarized the Rhineland in direct violation of the Versailles and Locarno treaties, receiving little response from other European powers.[15] This strategy of giving an aggressor what they supposedly need in order to maintain peace is called appeasement. When the Spanish Civil War broke out in July, Hitler and Mussolini supported fascist GeneralÐ"­simo 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.[16]

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 communismвЂ"and the Soviet Union in particularвЂ"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.[17]

War breaks out

Japanese forces during the Battle of WuhanIn mid-1937, following the Marco Polo Bridge Incident, Japan began a full invasion of China. The Soviets quickly lent support to China, effectively ending China's prior cooperation with Germany. Starting at Shanghai, the Japanese pushed Chinese forces back, capturing the capital Nanjing in December. In June of 1938 Chinese forces stalled the Japanese advance by flooding the Yellow River. Though this bought time to prepare their defenses at Wuhan, the city was still taken by October.[18] During this time, Japanese and Soviet forces engaged in a minor skirmish at Lake Khasan; in May of 1939, they became involved in a more serious border war.[19]

In Europe, Germany and Italy were becoming bolder. In March 1938, Germany annexed Austria, again provoking little response from other European powers.[20] Encouraged, Hitler began making claims on the Sudetenland; France and Britain conceded these for a promise of no further territorial demands.[21] Germany soon reneged, and in March 1939 fully occupied Czechoslovakia.

Soviet and German officers in PolandAlarmed, and with Hitler making further demands on Danzig, France and Britain guaranteed their support for Polish independence; when Italy conquered Albania in April, the same guarantee was extended to Romania and Greece.[22] The Soviet Union also attempted to ally with France and Britain, but was rebuffed due to western suspicions about Soviet motives and capability.[23] Shortly after the Franco-British pledges to Poland, Germany and Italy formalized their own alliance with the Pact of Steel; following this, in a move that shocked all