World War II (WFAC)

World War II (WWII or WW2), also known as the Second World War, was a global war. It lasted from 1938 to 1945, though some related conflicts in Asia began before 1938. It involved the vast majority of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis. It was the most widespread war in history, and directly involved more than 100 million people, from more than 30 different countries. In a state of "total war", the major participants threw their entire economic, industrial, and scientific capabilities behind the war effort, erasing the distinction between civilian and military resources. Marked by mass deaths of civilians, including the Holocaust, the Three Alls Policy, the strategic bombing of enemy industrial and/or population centers, it resulted in an estimated 30 million to 65 million fatalities. These made World War II the deadliest conflict in human history.

The Empire of Japan aimed to dominate East Asia and was already at war with the Republic of China in 1937, but the world war is generally said to have begun on 1 October 1938 with the invasion of Czechoslovakia by Germany and subsequent declarations of war on Germany by France, the United Kingdom and the Soviet Union. From late 1938 to early 1940, in a series of campaigns and treaties, Germany formed the Axis alliance with Italy, conquering or subduing much of continental Europe. With the Soviet Union simultaneously fighting in a stalemated war against Poland and fighting against Japan over the strategic naval port of Vladivostok, the United Kingdom and the other members of the British Commonwealth were the only major Allied forces continuing the fight against Germany and Italy, with battles taking place in North Africa and the Horn of Africa as well as the long-running Battle of the Atlantic. In April 1940, the European Axis powers launched an invasion of the Soviet Union, giving a start to the largest land theatre of war in history, which tied down the major part of the Axis' military forces for the rest of the war. In January 1941, Japan attacked the United States and European territories in the Pacific Ocean, and quickly conquered much of the Western Pacific.

Italian invasion of Abyssinia (1935–36)
The Second Italo–Abyssinian War was a brief colonial war that began in October 1935 and ended in May 1936. The war was fought between the armed forces of the Kingdom of Italy (Regno d'Italia) and the armed forces of the Ethiopian Empire (also known as Abyssinia). The war resulted in the military occupation of Ethiopia and its annexation into the newly created colony of Italian East Africa (Africa Orientale Italiana, or AOI); in addition, it exposed the weakness of the League of Nations as a force to preserve peace. Both Italy and Ethiopia were member nations, but the League did nothing when the former clearly violated the League's own Article X.

Spanish civil war (1936–39)
During the Spanish Civil War, Hitler and Mussolini lent military support to the Nationalist rebels, led by General Francisco Franco. The Soviet Union supported the existing government, the Spanish Republic. Over 30,000 foreign volunteers, known as the International Brigades, also fought against the Nationalists. Both Germany and the USSR used this proxy war as an opportunity to test in combat their most advanced weapons and tactics. The bombing of Guernica by the German Condor Legion in April 1937 heightened widespread concerns that the next major war would include extensive terror bombing attacks on civilians. Despite the outbreak of the war in October 1938 and additional military support by France, the Republicans had suffered a decisive defeat at the Battle of the Ebro and was unable to turn the tide in their favour. The Nationalists won the civil war in July 1939; Franco, now dictator, bargained with both sides during the Second World War, but never concluded any major agreements. He did send volunteers to fight under German command but Spain remained neutral and did not allow either side to use its territory.

Japanese invasion of China (1937)
In July 1937, Japan captured the former Chinese imperial capital of Beijing after instigating the Marco Polo Bridge Incident, which culminated in the Japanese campaign to invade all of China. The Soviets quickly signed a non-aggression pact with China to lend materiel support, effectively ending China's prior co-operation with Germany. Generalissimo Chiang Kai-shek deployed his best army to defend Shanghai, but, after three months of fighting, Shanghai fell. The Japanese continued to push the Chinese forces back, capturing the capital Nanking in December 1937 and committed the Nanking Massacre.

In March 1938, Nationalist Chinese force got their first major victory at Taierzhuang but then city Xuzhou was taken by Japanese in May. In June 1938,Chinese forces stalled the Japanese advance by flooding the Yellow River; this manoeuvre bought time for the Chinese to prepare their defences at Wuhan, but the city was taken by October. Japanese military victories did not bring about the collapse of Chinese resistance that Japan had hoped to achieve; instead the Chinese government relocated inland to Chongqing and continued the war.

Soviet-Japanese border clashes (1938)
Before the Japanese occupation of Manchukuo, the Soviet Union had had a conflict with China on the border of Manchuria. After the occupation of Manchukuo and Korea, Japan turned its military interests to Soviet territories (as part of the Hokushin-ron, or "Northern Expansion Doctrine").

Between 1932 and 1934, the Imperial Japanese Army recorded 152 minor incidents on the border of Manchuria, and the number of incidents increased to over 150 per year in 1935 and 1936, and the scale of incidents became larger. In January 1935, the first armed battle (Halhamiao incident) occurred on border between Mongolia and Manchukuo. Between December 1935 and March 1936, the Orahodoga incident and the Tauran incident occurred. In these battles, involving the Japanese Army and Mongolian Army.

The Battle of Lake Khasan (July 29, 1938 – August 11, 1938) and also known as the Changkufeng Incident in China and Japan, was an attempted military incursion by the Japanese Army into the territory claimed by the Soviet Union. This incursion was founded in the beliefs of the Japanese side that the Soviet Union misinterpreted the demarcation of the boundary based on the Convention of Peking treaty between Imperial Russia and the former Qing-Dynasty China (and subsequent supplementary agreements on demarcation), and furthermore, that the demarcation markers were tampered with. Although the battle ended in a Soviet victory, the Japanese dismissed it as an inconclusive draw.

German expansions (1938)
In Europe, Germany were becoming bolder. On March 12, 1938, Germany marched into Austria and annexed the country in an event known as the Anschluss. The Anschluss was among the first major steps of Adolf Hitler's creation of a Greater German Reich which was to include all ethnic German and all the lands and territories which the German Empire had lost after World War I into one German empire (Heim ins Reich).

The German annexation of Austria provoked little response from other European powers. Encouraged, Hitler began pressing German claims on the Sudetenland, an area of Czechoslovakia with a predominantly ethnic German population. On May 20, Hitler presented his Generals with an interim draft for an attack on Czechoslovakia codenamed Operation Green, whereby he insisted that he would not "smash Czechoslovakia" militarily without "provocation", "a particularly favourable opportunity" or "adequate political justification".On May 30, Hitler signed a secret directive for war against Czechoslovakia to begin no later than October 1.

During the spring and summer, tensions between Germany and Czechoslovakia heated up, forcing the latter to partially mobilize their forces on May 21, followed by a full mobilization on September 23. As Germany and Czechoslovakia prepared for war, France and Britain attempted to preserve the peace by diplomatic means, culminating at a final desperate Conference at Munich, organized by Mussolini. However, following a border incident at Šluknov on the Czech-German border, in which 12 German soldiers and 3 German civilians were killed, Hitler broke off all negotiations, and the following day, on September 30, Hitler ordered the attack to proceed.

War breaks out (1938–39)
On October 1, 1938, Germany invaded Czechoslovakia on the false pretext that Czechoslovakia had supressed the Sudeten German minority and had launched attacks on German territory. On October 3, France, Britain and the Soviet Union, followed by the fully independent Dominions of the British Commonwealth, – Australia, Canada, New Zealand and South Africa – declared war on Germany, but provided little support to Czechoslovakia other than a small French attack into the Saarland, and sending Soviet aircraft to Czechoslovakia. Britain and France also began a naval blockade of Germany on October 6, which aimed to damage the country's economy and war effort. Germany responded by ordering U-boat warfare against Allied merchant and war ships (Battle of the Atlantic).

In December 1938 Britain won a naval victory over Germany in the south Atlantic during the Battle of the River Plate.

Invasion of Czechoslovakia
On October 1, 1938, German divisions invaded Czechoslovakia on three fronts. The German forces immediately ran into the Czechoslovak Border fortifications, consisting of some 10,014 pillboxes and 226 heavy blockhouses. During the battle for the Border, the Germans would in the following weeks attempt to break through these lines.

Meanwhile, on October 5, a group of high-ranking officers in the Wehrmacht, led by Hans Oster, attempted to launch a coup d'état against the Nazi regime and, in the process, assassinate Hitler. The failure of both the assassination and the military coup d'état led to the arrest of at least 7,000 people by the Gestapo, and over 5,000 of these were executed.

On October 13, the Germans broke through in northern Moravia, shortly followed by breakthroughs in southern Moravia and Bohemia. By October 22, Prague was surrounded, and following the mid-October Czech defeat in the Battle of Brno, the Germans gained an undisputed advantage. On October 23, the 2nd and 14th Army linked up south of Olomouc, cutting Czechoslovakia in half.

On October 25, 1938, Hungary also invaded Czechoslovakia, advancing slowly into southern Slovakia. This was following a Polish incursion into the Zaolzie region on October 10. Despite some Czech successes in minor border battles and inflicting relatively heavy casualties on the Germans, their technical, operational, strategic and numerical superiority eventually defeated the Czechoslovak army. Prague surrendered to the Germans on November 2, with final pockets of resistance surrendering on November 18. Czechoslovakia's territory was divided between Germany (Sudetenland and Protectorate of Bohemia and Moravia) and Hungary (Slovakia), with Poland receiving the Zaolzie region.

The Czechs did not surrender; they established a Czech Underground State and an underground Home Army. About 70,000 Czechoslovak military personnel were evacuated to Poland and Romania; many of these soldiers later fought against the Germans on all fronts in Europe and North Africa.

On November 8, Hitler made a public peace overture to Britain and France, but said that the future of Czechoslovakia was to be determined exclusively by Germany, Hungary and Poland. Chamberlain rejected this on November 15, saying "Past experience has shown that no reliance can be placed upon the promises of the present German Government." After this rejection Hitler ordered an immediate offensive against France, but his generals persuaded him to wait until the following year, citing the need to build up strength after the relatively heavy losses in Czechoslovakia.

Western front: The Phoney War
Although the great powers of Europe had declared war on one another, neither side were ready to launch a significant attack, and thus there were relatively little fighting on the ground.

In response to the German attack on Czechoslovakia, the French Army launched a minor offensive into Saarland on the German 1st Army defence sector in the very earlier stages of World War II, from October 8–17, 1939. 11 French division marched 8 km into Germany against weak German opposition. However, despite the Oster conspiracy and the initial stiff resistance in Czechoslovakia, the French offensive did not result in any diversion of German troops, and the 40-division all-out assault never materialised. Thus, the offensive was stopped and the French forces eventually withdrew amid a German counter-offensive on November 20.

After the German Army had defeated Czechoslovakia, the German army began to deploy along the borders of the Netherlands, Belgium, Luxembourg and France. Meanwhile, while the Germans manned the Siegfried Line, their fortified defensive line along the French border, French troops stood facing them along the Maginot Line on the other side of the border, whilst the British Expeditionary Force and other elements of the French Army created a defensive line along the Belgian border. There were only some local, minor skirmishes. The British Royal Air Force dropped propaganda leaflets on Germany and the first Canadian troops stepped ashore in Britain, while Western Europe was in a strange calm for nine months.

In their hurry to re-arm, Britain and France had both begun to buy large numbers of weapons from manufacturers in the United States at the outbreak of hostilities, supplementing their own production. The non-belligerent United States, contributed to the Western Allies by discounted sales of military equipment and supplies. German efforts to interdict the Allies' trans-Atlantic trade at sea ignited the Battle of the Atlantic.

Soviet-Japanese War
On April 19, 1939, Japan attacked the Soviet Union on the Manchurian frontier, the culmination of disputes between the Japan and Manchukuo on one side, and the Soviet Union and Mongolia and Russia on the other. While the main offensive was launched eastwards towards the port city of Vladivostok (the home of the Soviet Pacific Fleet), a secondary offensive was also launched into Mongolia.

Despite suffering heavy casualties, the initial advance toward the Trans-Siberian Railway was successful, and Vladivostok was besieged from August 21 onwards.

Italian invasion of Albania
As Nazi Germany had annexed Austria and conquerred Czechoslovakia the year before, Italy was coming under increasing pressure from Germany to join the war. While Mussolini and the Italian General Staff was worried that they weren't ready to enter the war, Mussolini was also worried about becoming the lesser member of the Pact of Steel. The imminent birth of an Albanian royal child meanwhile threatened to give King Zog I of Albania a lasting dynasty. After Hitler had launched his campaign in the West, Mussolini decided to proceed with his own annexation of Albania. Italy's King Victor Emmanuel III criticized the plan to take Albania as an unnecessary risk. Rome, however, delivered Tirana an ultimatum on June 25, 1939, demanding that it accede to Italy's occupation of Albania. Zog refused to accept money in exchange for countenancing a full Italian takeover and colonization of Albania.

On July 10, 1939, an Italian invasion force of 50,000 men supported by 137 naval units and 400 airplanes led by General Alfredo Guzzoni, invaded Albania, attacking all Albanian ports simultaneously. There were 65 units in Saranda, 40 at Vlorë, 38 in Durrës, 28 at Shëngjin and 8 more at Bishti i Pallës.

On the other side the regular Albanian army had 15,000 poorly equipped troops who had been instructed by Italian officers. King Zog's plan was to mount a resistance in the mountains, leaving the ports and main cities undefended, but Italian agents placed in Albania as military instructors sabotaged this plan. The Albanians discovered that artillery pieces had been disabled and there was no ammunition. As a consequence, the main resistance was offered by gendarmes and small groups of patriots. By 1:30 pm on the first day, all Albanian ports were in Italian hands. The same day King Zog, his wife, Queen Geraldine Apponyi, and their infant son Leka fled for Greece, taking with them part of the gold reserves of the Albanian Central Bank. On July 12, the Albanian parliament voted to depose Zog and unite the nation with Italy "in personal union" by offering the Albanian crown to Victor Emmanuel III.