At the end of World War I the victorious nations formed the League of Nations for the purpose of airing international disputes, and of mobilizing its members for a collective effort to keep the peace in the event of aggression by any nation against another or of a breach of the peace treaties. The United States, imbued with isolationism, did not become a member. The League failed in its first test. In 1931 the Japanese, using as an excuse the explosion of a small bomb under a section of track of the South Manchuria Railroad (over which they had virtual control), initiated military operations designed to conquer all of Manchuria. After receiving the report of its commission of inquiry, the League adopted a resolution in 1933 calling on the Japanese to withdraw. Thereupon, Japan resigned from the League. Meanwhile, Manchuria had been overrun and transformed into a Japanese puppet state under the name of Manchukuo. Beset by friction and dissension among its members, the League took no further action.

In 1933 also, Adolf Hitler came to power as dictator of Germany and began to rearm the country in contravention of the provisions of the Treaty of Versailles. He denounced the provisions of that treaty that limited German armament and in 1935 reinstituted compulsory military service. That year the Italian dictator Benito Mussolini began his long-contemplated invasion of Ethiopia, which he desired as an economic colony. The League voted minor sanctions against Italy, but these had slight practical effect. British and French efforts to effect a compromise settlement failed, and Ethiopia was completely occupied by the Italians in 1936.

Alarmed by German rearmament, France sought an alliance with the USSR. Under the pretext that this endangered Germany, Hitler remilitarized the Rhineland in 1936. It was a dangerous venture, for Britain and France could have overwhelmed Germany, but, resolved to keep the peace, they took no action. Emboldened by this success, Hitler intensified his campaign for Lebensraum (space for living) for the German people. He forcibly annexed Austria in March 1938, and then, charging abuse of German minorities, threatened Czechoslovakia. In September, as Hitler increased his demands on the Czechs and war seemed imminent, the British and French arranged a conference with Hitler and Mussolini. At the Munich Conference they agreed to German occupation of the Sudetenland, Hitler's asserted last claim, in the hope of maintaining peace. This hope was short lived, for in March 1939, Hitler took over the rest of Czechoslovakia and seized the former German port of Memel from Lithuania. There followed demands on Poland with regard to Danzig (Gdansk) and the Polish Corridor. The Poles remained adamant, and it became clear to Hitler that he could attain his objectives only by force. After surprising the world with the announcement of a nonaggression pact with his sworn foe, the Soviet Union, he sent his armies across the Polish border on Sept. 1, 1939. Britain and France, pledged to support Poland in the event of aggression, declared war on Germany two days later.

As the Germans ravaged Poland, the Russians moved into the eastern part of the country and began the process that was to lead to the absorption in 1940 of Latvia, Estonia, and Lithuania. They also made demands on Finland. The recalcitrant Finns were subdued in the Winter War of 1939-1940, but only after dealing the Russians several humiliating military reverses.

Meanwhile, Japan had undertaken military operations for the subjugation of China proper, and was making preparations for the expansion of its empire into Southeast Asia and the rich island groups of the Southwest Pacific. Mussolini watched the progress of his fellow dictator, Hitler, while preparing to join in the war at a propitious moment.

Military Course of the War

The bitter struggles and the enormous casualties suffered by Great Britain and France in World War I had engendered in their military leaders a defensive attitude with a reliance on such permanent fortifications as the Maginot Line and on blockade as means of subduing a resurgent Germany. Placing their faith in the impotent League of Nations, both countries neglected the development of armaments and allowed those they possessed and their armed forces to deteriorate. The Germans, on the other hand, smarting under their failure in World War I to capitalize on initial breakthroughs of the Allied lines because of lack of sustained power, developed fast, hard-hitting tank-airplane forces and the strategy of the blitzkrieg (lightning war). Since they had been disarmed by the Allies, they were unencumbered by obsolescent armaments and could equip their forces with the most modern weapons. As a result, initial German operations met with surprisingly rapid success.

In less than a month, Poland had been conquered. There followed an inactive period (dubbed the Phony War) that lasted until April 1940. Then, despite Allied intervention, the Germans quickly seized Denmark and Norway. In May the blitzkrieg struck the western front in all its fury. Within six weeks the British had been driven from the Continent, and the French had been forced to surrender. The speed of the advance also surprised Hitler, who was not ready to follow his success with an invasion of the British Isles. The Luftwaffe, called upon to soften the islands and gain air superiority while preparations were made for invasion, received a stunning defeat at the hands of the small but highly competent and brave Royal Air Force. Frustrated in the west, Hitler turned against the USSR in June 1941. In a series of brilliant military maneuvers in which several million Russians were captured, he reached the gates of Moscow in December, only to be stopped by bad weather and Russian reinforcements rushed to defend the city.

Meanwhile, Mussolini sought to realize his dream of an Italian Mediterranean empire. In the late summer and fall of 1940 he launched an offensive from Libya against the British in Egypt and an invasion of Greece from Albania (which he had occupied in 1939). Both enterprises eventually proved disastrous for the Italians, and German forces were sent to their rescue. Greece fell to the Germans, but they met stiff British opposition in Africa. In December 1941, Japan thought the time ripe to extend her empire into a Greater East Asia Coprosperity Sphere which it did very rapidly against meager opposition. It was the Japanese plan to fortify this area so strongly as to withstand American counterattacks and eventually gain a negotiated peace based on the status quo. The attacks on Pearl Harbor and the Philippines brought the United States into the war and greatly altered the balance of power in favor of the Allies.

The year 1942 saw the turn of the tide for the Allies. In June, Japanese naval airpower was decimated by the United States Navy in the Battle of Midway. Having been repulsed at Moscow, Hitler turned to the Caucasus, but the Germans were severely defeated and turned back at Stalingrad (now Volgograd) by the Russians in the closing months of the year. At the same time the British dealt the Germans and Italians a defeat at El Alamein that sent them reeling in retreat westward along the African Mediterranean coast. In Tunisia they encountered newly landed British and American forces and were expelled from Africa in May 1943.

The Allies now had the initiative and, with the vast production facilities of the United States in full operation, took the offensive on all fronts. Resistance was bitter, and progress slow though inexorable. From bases in Africa the Allies invaded and captured Sicily in July-August 1943. In September, Italy was forced out of the war. British (The term "British, as applied to military forces, includes where appropriate other Commonwealth forces--Canadian, Australian, New Zealand, South African, and Indian--which performed outstandingly during the war.), American, and French forces began a methodical and relentless advance up the Italian Peninsula against the Germans, who had been rushed in to defend it. After Stalingrad the Russians, in a series of alternating offensives, gradually forced the Germans back with heavy losses, until by late April 1945 they were approaching Berlin.

Following a massive buildup of troops, air and naval power, and equipment in the British Isles, American, British, and French troops landed on the Normandy coast of France in June 1944 and pressed the Germans back to the West Wall. There, in December, the Germans launched a final counterattack, which failed. Aided by troops landed in southern France from Italy, the Allies forced the Germans back across the Rhine River and deep into Germany. Assailed on all sides, and their major cities devastated by aerial bombardment, the Germans surrendered on May 7, 1945.

Because of a lack of resources, Allied strategy had envisioned the prior defeat of Germany while remaining on the defensive against the Japanese. Only after victory in Europe would the full Allied power be applied to Japan. American industrial production increased so rapidly, however, that limited offensives could be initiated against the Japanese as early as August 1942. Thereafter, a persistent two-pronged offensive across the Central Pacific and along the Solomon Islands-New Guinea axis steadily pushed the Japanese back. By the fall of 1944, American forces were landing in the Philippines, and they regained the islands the next spring. Then the island of Okinawa, at the threshold of Japan proper, was captured, and preparations were begun for the invasion of the home islands. Meanwhile, the Japanese position in Asia progressively deteriorated. By the summer of 1945, with its navy and air force virtually destroyed, its cities at the mercy of American aircraft, and cut off from sources of supply of much-needed raw materials, the Japanese foresaw doom. The dropping of two Atomic Bombs on Japanese cities and the Soviet invasion of Manchuria hastened their decision to capitulate, which they did on August 14.

Diplomatic History of the War and Postwar Period

The League of Nations having failed through inertia and internal discord to prevent war, the major powers aligned themselves in rival groups. In September 1940, Germany, Italy, and Japan signed the Tripartite Pact in Berlin, formalizing the Axis coalition. Hitler's invasion forced the Russians into the Franco-British camp. As the war progressed, the United States departed from its policy of strict neutrality and rendered greater and greater aid short of war to the beleaguered Allies. Blocked in negotiations with the United States from furthering its aims of expansion, Japan attacked the American base at Pearl Harbor in December 1941 and forced the United States into the war.

Meanwhile, in August 1941, Franklin D. Roosevelt and Winston Churchill met on shipboard off Newfoundland and subsequently issued the Atlantic Charter, in which they subscribed to certain general principles for achieving peace. The charter forbade territorial changes contrary to the wishes of the inhabitants; recognized the right of people to choose their own forms of government; promised greater freedom of trade and of the seas; and supported international cooperation to improve conditions of labor and social security. Armaments were to be reduced, and a permanent system of general security was to be created. The aggressor nations were to be disarmed. On Jan. 1, 1942, the United States, Great Britain, France, the USSR, China, and 21 other countries signed in Washington the Declaration by United Nations, pledging mutual assistance and promising not to enter into separate armistice or peace negotiations with the Axis powers. The member nations also subscribed to theAtlantic Charter's purposes and principles.

At the Casablanca Conference in January 1943, Roosevelt and Churchill--most probably to allay Joseph Stalin's suspicions of the loyalty of his allies--proclaimed a policy of unconditional surrender for Germany, Italy, and Japan as the only means of maintaining the peace. This policy may have prolonged the war, but it solidified the Allied nations and may have forestalled Soviet efforts toward a separate peace with Germany in 1943.

At the Teheran Conference in late 1943, Roosevelt, Churchill, and Stalin agreed on broad principles of operation for an international organization to mediate differences between nations and maintain peace. At Dumbarton Oaks in Washington in the fall of 1944 details were worked out, and it was decided to call the new organization the United Nations. The San Francisco Conference convened on April 25, 1945, to organize the United Nations; its charter was adopted unanimously on June 26.

War's end found the United States and the USSR the two greatest powers in the world. By the time of the signing of the Axis satellite treaties early in 1947, the two countries were drawing apart. Friction over the treaties with Austria, Germany, and Japan and Soviet aggressive designs in eastern Europe brought increasing tension, and by the end of 1948 their relationship could be considered one of cold war. In 1950 armed conflict arose in Korea between Soviet-backed Communist forces and United Nations forces led by the United States. The cold war between the East and West continued thereafter, with the Communists striving for world domination through subversion and infiltration, and the West seeking to frustrate their designs.