World War II or the Second World War was a global conflict between two alliances: the Allies and the Axis powers. Nearly all of the world's countries, including all of the great powers, participated in the conflict, and many invested all available economic, industrial, and scientific capabilities in pursuit of total war, blurring the distinction between civilian and military resources. Aircraft played a major role, enabling the strategic bombing of population centres and delivery of the only two nuclear weapons ever used in war. It was by far the deadliest conflict in history, resulting in 70–85 million fatalities. Millions died due to genocides, including the Holocaust, as well as starvation, massacres, and disease. In the wake of Axis defeat, Germany, Austria, Japan and Korea were occupied, and war crime tribunals were conducted against German and Japanese leaders.
The Battle of the Bulge, also known as the Ardennes Offensive, was the last major German offensive campaign on the Western Front during World War II which took place from 16 December 1944 to 25 January 1945. It was launched through the densely forested Ardennes region between Belgium and Luxembourg. The offensive was intended to stop Allied use of the Belgian port of Antwerp and to split the Allied lines, allowing the Germans to encircle and destroy each of the four Allied armies and force the western Allies to negotiate a peace treaty in the Axis powers' favor.
The Tehran Conference was a strategy meeting of Joseph Stalin, Franklin D. Roosevelt, and Winston Churchill from 28 November to 1 December 1943. It was held at the Soviet Union's embassy at Tehran in Iran. It was the first of the World War II conferences of the "Big Three" Allied leaders and closely followed the Cairo Conference, which had taken place on 22–26 November 1943, and preceded the 1945 Yalta and Potsdam conferences. Although the three leaders arrived with differing objectives, the main outcome of the Tehran Conference was the Western Allies' commitment to open a second front against Nazi Germany. The conference also addressed the 'Big Three' Allies' relations with Turkey and Iran, operations in Yugoslavia and against Japan, and the envisaged postwar settlement. A separate contract signed at the conference pledged the Big Three to recognize Iranian independence.
The Yalta Conference, held 4–11 February 1945, was the World War II meeting of the heads of government of the United States, the United Kingdom and the Soviet Union to discuss the postwar reorganization of Germany and Europe. The three states were represented by President Franklin D. Roosevelt, Prime Minister Winston Churchill, and General Secretary Joseph Stalin. The conference was held near Yalta in Crimea, Soviet Union, within the Livadia, Yusupov, and Vorontsov palaces.
The Cairo Conference also known as the First Cairo Conference, one of the 14 summit meetings during World War II, took place on November 22–26, 1943. The Conference was held at Cairo in Egypt between China, the United Kingdom and the United States. It outlined the Allied position against the Empire of Japan during World War II and made decisions about post-war Asia. The conference was attended by Chairman Chiang Kai-shek, British Prime Minister Winston Churchill and US President Franklin D. Roosevelt.
The military history of the United Kingdom in World War II covers the Second World War against the Axis powers, starting on 3 September 1939 with the declaration of war by the United Kingdom and France, followed by the UK's Dominions, Crown colonies and protectorates on Nazi Germany in response to the invasion of Poland by Germany. There was little, however, the Anglo-French alliance could do or did do to help Poland. The Phoney War culminated in April 1940 with the German invasion of Denmark and Norway. Winston Churchill became prime minister and head of a coalition government in May 1940. The defeat of other European countries followed – Belgium, the Netherlands, Luxembourg and France – alongside the British Expeditionary Force which led to the Dunkirk evacuation in June 1940.
The European theatre of World War II was one of the two main theatres of combat during World War II. It saw heavy fighting across Europe for almost six years, starting with Germany's invasion of Poland on 1 September 1939 and ending with the Western Allies conquering most of Western Europe, the Soviet Union conquering most of Eastern Europe including the German capital Berlin, and Germany's unconditional surrender on 8 May 1945 although fighting continued elsewhere in Europe until 25 May. On 5 June 1945, the Berlin Declaration proclaiming the unconditional surrender of Germany to the four victorious powers was signed. The Allied powers fought the Axis powers on two major fronts, but there were other fronts varying in scale from the Italian campaign, to the Polish Campaign, as well as in a strategic bombing offensive and in the adjoining Mediterranean and Middle East theatre.
The final battles of the European theatre of World War II continued after the definitive surrender of Nazi Germany to the Allies, signed by Field marshal Wilhelm Keitel on 8 May 1945 in Karlshorst, Berlin. After German leader Adolf Hitler's suicide and handing over of power to grand admiral Karl Dönitz on the last day of April 1945, Soviet troops conquered Berlin and accepted surrender of the Dönitz-led government. The last battles were fought on the Eastern Front which ended in the total surrender of all of Nazi Germany’s remaining armed forces such as in the Courland Pocket in western Latvia from Army Group Courland in the Baltics surrendering on 10 May 1945 and in Czechoslovakia during the Prague offensive on 11 May 1945.
Operation Sledgehammer was an Allied plan for a cross-Channel invasion of Europe during World War II, as the first step in helping to reduce pressure on the Soviet Red Army by establishing a Second Front. It was to be executed in 1942 and acted as a contingency alternative to Operation Roundup, the original Allied plan for the invasion of Europe in 1943. Allied forces were to seize the French Atlantic ports of either Brest or Cherbourg and areas of the Cotentin Peninsula during the early autumn of 1942, and amass troops for a breakout in the spring of 1943.
The Cold War originated in the breakdown of relations between the two main victors in World War II: United States and the Soviet Union, and their respective allies, the Western Bloc and the Eastern Bloc, in the years 1945–1949.
The Western Front was a military theatre of World War II encompassing Denmark, Norway, Luxembourg, Belgium, the Netherlands, the United Kingdom, France, and Germany. The Italian front is considered a separate but related theatre. The Western Front's 1944–1945 phase was officially deemed the European Theater by the United States, whereas Italy fell under the Mediterranean Theater along with North Africa. The Western Front was marked by two phases of large-scale combat operations. The first phase saw the capitulation of Luxembourg, Netherlands, Belgium, and France during May and June 1940 after their defeat in the Low Countries and the northern half of France, and continued into an air war between Germany and Britain that climaxed with the Battle of Britain. The second phase consisted of large-scale ground combat, which began in June 1944 with the Allied landings in Normandy and continued until the defeat of Germany in May 1945 with its invasion.
Western betrayal is the view that the United Kingdom, France, and sometimes the United States failed to meet their legal, diplomatic, military, and moral obligations with respect to the Czechoslovak and Polish states during the prelude to and aftermath of World War II. It also sometimes refers to the treatment of other Central and Eastern European states at the time.
Operation Silver Fox from 29 June to 17 November 1941, was a joint German–Finnish military operation during the Continuation War on the Eastern Front of World War II against the Soviet Union. The objective of the offensive was to cut off and capture the key Soviet Port of Murmansk through attacks from Finnish and Norwegian territory.
The Soviet invasion of Manchuria, formally known as the Manchurian Strategic Offensive Operation or simply the Manchurian Operation, began on 9 August 1945 with the Soviet invasion of the Japanese puppet state of Manchukuo. It was the largest campaign of the 1945 Soviet–Japanese War, which resumed hostilities between the Union of Soviet Socialist Republics and the Empire of Japan after almost six years of peace.
The Allied intervention in the Russian Civil War consisted of a series of multi-national military expeditions that began in 1918. The initial impetus behind the interventions was to secure munitions and supply depots from falling into the German Empire's hands, particularly after the Bolsheviks signed the Treaty of Brest-Litovsk, and to rescue the Allied forces that had become trapped within Russia after the 1917 October Revolution. After the Armistice of 11 November 1918, the Allied plan changed to helping the White forces in the Russian Civil War. After the Whites collapsed, the Allies withdrew their forces from Russia by 1925.
The Allies, formally referred to as the United Nations from 1942, were an international military coalition formed during World War II (1939–1945) to oppose the Axis powers. Its principal members by the end of 1941 were the "Big Four" – the United Kingdom, United States, Soviet Union, and China.
The Soviet–Japanese War, known in Mongolia as the Liberation War of 1945, was a campaign of the Second World War that began with the Soviet invasion of Japanese-controlled Manchukuo following the Soviet declaration of war against Japan on 9 August 1945. The Soviet Union and Mongolian People's Republic toppled the Japanese puppet states of Manchukuo in Manchuria and Mengjiang in Inner Mongolia, as well as northern Korea, Karafuto on the island of Sakhalin, and the Kuril Islands. The defeat of Japan's Kwantung Army helped bring about the Japanese surrender and the end of World War II. The Soviet entry into the war was a significant factor in the Japanese government's decision to surrender unconditionally, as it was made apparent that the Soviet Union was not willing to act as a third party in negotiating an end to hostilities on conditional terms.
Operation Overlord was the codename for the Battle of Normandy, the Allied operation that launched the successful liberation of German-occupied Western Europe during World War II. The operation was launched on 6 June 1944 (D-Day) with the Normandy landings. A 1,200-plane airborne assault preceded an amphibious assault involving more than 5,000 vessels. Nearly 160,000 troops crossed the English Channel on 6 June, and more than two million Allied troops were in France by the end of August.
The percentages agreement was a secret informal agreement between British Prime Minister Winston Churchill and Soviet leader Joseph Stalin during the Fourth Moscow Conference in October 1944. It gave the percentage division of control over Eastern European countries, dividing them into spheres of influence. It is also known as the naughty document, a nickname coined by Churchill himself due to his concerns regarding American reaction to any deal with such strong imperialist undertones, although in reality U.S. President Franklin Roosevelt was consulted tentatively and conceded to the agreement. The content of the agreement was first made public by Churchill in 1953 in the final volume of his memoir. The US ambassador Averell Harriman, who was supposed to represent Roosevelt in these meetings, was excluded from this discussion.
United States war plans for a conflict with the Soviet Union (USSR) were formulated and revised on a regular basis between 1945 and 1950. Although most were discarded as impractical, they nonetheless would have served as the basis for action had a conflict occurred. At no point was it considered likely that the Soviet Union or United States would resort to war, only that one could potentially occur as a result of a miscalculation. Planning was conducted by agencies of the Joint Chiefs of Staff, in collaboration with planners from the United Kingdom and Canada.
