World war II

World War II War breaks out in Europe On 1 September 1939, Germany and Slovakia — a client state in 1939 — attacked Poland. On 3 September 1939 after Germany failed to withdraw in accordance with French and British demands, France and Britain, followed by the countries of the Commonwealth, declared war on Germany but provided little military support to Poland other than a small French attack into the Saarland.On 17 September 1939, after signing an armistice with Japan, the Soviets launched their own invasion of Poland.By early October, Poland was divided among Germany, the Soviet Union, Lithuania and Slovakia, although Poland never officially surrendered and continued the fight outside its borders.At the same time as the battle in Poland, Japan launched its first attack against Changsha, a strategically important Chinese city, but was repulsed by late September. Common parade of German Wehrmacht and Soviet Red Army on 23 September 1939 in Brest, Eastern Poland at the end of the Invasion of Poland. At centre is Major General Heinz Guderian and at right is Brigadier Semyon Krivoshein.Following the invasion of Poland and a German-Soviet treaty governing Lithuania, the Soviet Union forced the Baltic countries to allow it to station Soviet troops in their countries under pacts of "mutual assistance."Finland rejected territorial demands and was invaded by the Soviet Union in November 1939.The resulting conflict ended in March 1940 with Finnish concessions.France and the United Kingdom, treating the Soviet attack on Finland as tantamount to entering the war on the side of the Germans, responded to the Soviet invasion by supporting the USSR's expulsion from the League of Nations.In June 1940, the Soviet Armed Forces invaded and occupied the neutral Baltic States. In Western Europe, British troops deployed to the Continent, but in a phase nicknamed the Phoney War by the British and "Sitzkrieg" (sitting war) by the Germans, neither side launched major operations against the other until April 1940.The Soviet Union and Germany entered a trade pact in February of 1940, pursuant to which the Soviets received German military and industrial equipment in exchange for supplying raw materials to Germany to help circumvent a British blockade. In April 1940, Germany invaded Denmark and Norway to secure shipments of iron ore from Sweden, which the Allies would try to disrupt.Denmark immediately capitulated, and despite Allied support, Norway was conquered within two months.British discontent over the Norwegian campaign led to the replacement of Prime Minister Neville Chamberlain by Winston Churchill on 10 May 1940. Axis advances On that same day, Germany invaded France, Belgium, the Netherlands, and Luxembourg.The Netherlands and Belgium were overrun using blitzkrieg tactics in a few days and weeks, respectively.The French fortified Maginot Line was circumvented by a flanking movement through the thickly wooded Ardennes region,mistakenly perceived by French planners as an impenetrable natural barrier against armoured vehicles.British troops were forced to evacuate the continent at Dunkirk, abandoning their heavy equipment by the end of the month. On 10 June, Italy invaded, declaring war on both France and the United Kingdom twelve days later France surrendered and was soon divided into German and Italian occupation zones,and an unoccupied rump state under the Vichy Regime. On 14 July, the British attacked the French fleet in Algeria to prevent its possible seizure by Germany. With France neutralised, Germany began an air superiority campaign over Britain (the Battle of Britain) to prepare for an invasion.The campaign failed, and the invasion plans were cancelled by September. Using newly captured French ports, the German Navy enjoyed success against an over-extended Royal Navy, using U-boats against British shipping in the Atlantic.Italy began operations in the Mediterranean, initiating a siege of Malta in June, conquering British Somaliland in August, and making an incursion into British-held Egypt in September 1940. Japan increased its blockade of China in September by seizing several bases in the northern part of the now-isolated French Indochina. Throughout this period, the neutral United States took measures to assist China and the Western Allies. In November 1939, the American Neutrality Act was amended to allow 'Cash and carry' purchases by the Allies.In 1940, following the German capture of Paris, the size of the United States Navy was significantly increased and, after the Japanese incursion into Indochina, the United States embargoed iron, steel and mechanical parts against Japan.In September, the United States further agreed to a trade of American destroyers for British bases.Still, a large majority of the American public continued to oppose any direct military intervention into the conflict well into 1941. At the end of September 1940, the Tripartite Pact united Japan, Italy, and Germany to formalize the Axis Powers.The Tripartite Pact stipulated that any country, with the exception of the Soviet Union, not in the war which attacked any Axis Power would be forced to go to war against all three.During this time, the United States continued to support the United Kingdom and China by introducing the Lend-Lease policy authorizing the provision of war materiel and other items and creating a security zone spanning roughly half of the Atlantic Ocean where the United States Navy protected British convoys.As a result, Germany and the United States found themselves engaged in sustained naval warfare in the North and Central Atlantic by October 1941, even though the United States remained officially neutral. The Axis expanded in November 1940 when Hungary, Slovakia, and Romania joined the Tripartite Pact.These countries participated in the subsequent invasion of the USSR, with Romania making the largest contribution to recapture territory ceded to the USSR and pursue its leader Ion Antonescu's desire to combat communism.In October 1940, Italy invaded Greece but within days was repulsed and pushed back into Albania, where a stalemate soon occurred.In December 1940, British Commonwealth forces began counter-offensives against Italian forces in Egypt and Italian East Africa.By early 1941, with Italian forces having been pushed back into Libya by the Commonwealth, Churchill ordered a dispatch of troops from Africa to bolster the Greeks.The Italian Navy also suffered significant defeats, with the Royal Navy putting three Italian battleships out of commission by carrier attack at Taranto, and neutralising several more warships at Cape Matapan. The Germans soon intervened to assist Italy. Hitler sent German forces to Libya in February, and by the end of March they had launched an offensive against the diminished Commonwealth forces.In under a month, Commonwealth forces were pushed back into Egypt with the exception of the besieged port of Tobruk.The Commonwealth attempted to dislodge Axis forces in May and again in June, but failed on both occasions.In early April, following Bulgaria's signing of the Tripartite Pact, the Germans intervened in the Balkans by invading Greece and Yugoslavia following a coup; here too they made rapid progress, eventually forcing the Allies to evacuate after Germany conquered the Greek island of Crete by the end of May. The Allies did have some successes during this time. In the Middle East, Commonwealth forces first quashed a coup in Iraq which had been supported by German aircraft from bases within Vichy-controlled Syria,then, with the assistance of the Free French, invaded Syria and Lebanon to prevent further such occurrences.In the Atlantic, the British scored a much-needed public morale boost by sinking the German flagship Bismarck.Perhaps most importantly, during the Battle of Britain the Royal Air Force had successfully resisted the Luftwaffe's assault, and on 11 May 1941, Hitler called off the bombing campaign. In Asia, despite several offensives by both sides, the war between China and Japan was stalemated by 1940. In order to increase pressure on China by blocking supply routes, and to better position Japanese forces in the event of a war with the Western powers, Japan had seized military control of southern Indochina in August of that year, Chinese communists launched an offensive in Central China; in retaliation, Japan instituted harsh measures (the Three Alls Policy) in occupied areas to reduce human and material resources for the communists.Continued antipathy between Chinese communist and nationalist forces culminated in armed clashes in January 1941, effectively ending their co-operation.With the situation in Europe and Asia relatively stable, Germany, Japan, and the Soviet Union made preparations. With the Soviets wary of mounting tensions with Germany and the Japanese planning to take advantage of the European War by seizing resource-rich European possessions in Southeast Asia, the two powers signed the Soviet–Japanese Neutrality Pact in April 1941.By contrast, the Germans were steadily making preparations for an attack on the Soviet Union, amassing forces on the Soviet border.