The Second World War | ICSE Class 10 History & Civics Notes

This note covers the background and causes of the Second World War, the opposing powers, the invasion of Poland, Pearl Harbour, Hiroshima and Nagasaki, the defeat of the Axis powers, the formation of the United Nations, and the Cold War and its military alliances.

What was the background to the Second World War, and who participated?

The Second World War was a global armed conflict fought from 1939 to 1945. Its background lay partly in the unsettled peace following the First World War of 1914 to 1918. Territorial grievances, aggressive governments and unsuccessful attempts to prevent expansion contributed to another major conflict.

Aggression means an unprovoked armed attack by one country on another. Expansionism is the policy of extending a state's territory or control. These ideas connect events in Europe with Japan's wars in Asia, even though fighting developed differently in the two regions.

Which countries formed the Axis group?

The Axis powers were principally Germany, Italy and Japan. Germany's Adolf Hitler and Italy's Benito Mussolini led dictatorships, systems in which rulers exercised concentrated power and suppressed political opposition. Japan's military leadership pursued the extension of its empire in Asia.

Which countries formed the Allied group?

The Allies were the countries fighting the Axis powers. Britain and France fought Germany from 1939. The Soviet Union and the United States of America became major Allied participants in 1941. China fought against Japanese aggression. Countries entered the conflict at different times.

The Soviet Union, also called the Union of Soviet Socialist Republics or USSR, was a state led by its Communist Party. The United States of America is abbreviated as USA or US. Wartime cooperation between these powers later gave way to rivalry.

How were civilians involved?

Civilians are people who are not members of the armed forces. They experienced invasion, bombing and displacement. In Japan, wartime controls included the repression and imprisonment of dissidents, meaning people who opposed official policies; patriotic societies, many of them women's organisations, supported the war.

The conflict therefore involved more than soldiers and battlefields. Understanding it requires a distinction between the decisions of governments, the actions of armed forces and the experiences of populations living under attack or wartime restrictions.

Why did dissatisfaction with the Treaty of Versailles contribute to war?

The Treaty of Versailles was the peace settlement imposed on Germany in 1919 after the First World War. A treaty is a formal agreement between states. Many Germans regarded this settlement as humiliating and unfair, creating resentment that Hitler later used to gain support.

What were the principal grievances?

Germany lost territory and its overseas colonies. Its armed forces were restricted, and it had to accept responsibility for the war under the war guilt clause. Germany was also required to pay reparations, meaning compensation for war damage.

Rearmament means rebuilding or increasing armed forces and weapons. Hitler used promises of rearmament and restored national power to challenge the settlement. Treaty grievances thus supplied both a political appeal within Germany and a justification for changing Europe's existing arrangements.

How did resentment become a cause of another war?

The link was not simply that a harsh treaty automatically produced war. Resentment became dangerous when an expansionist dictatorship used it to support military action, while other powers failed to stop repeated challenges. The treaty created grievances; later political choices turned those grievances into aggressive policies.

Germany's renewed military strength also made its demands harder to resist. By the time Hitler invaded Poland in 1939, opposition to Versailles had become connected with a much wider programme of conquest. Explaining this connection is more precise than treating the treaty as the sole cause.

How did Fascism and Nazism increase the danger of war?

Fascism, associated with Mussolini's rule in Italy, was an authoritarian ideology, demanding obedience to strong central authority and stressing the supremacy of the state, obedience to a leader and aggressive nationalism. An ideology is a system of political beliefs. Nazism, Hitler's ideology in Germany, combined dictatorship and expansion with racist doctrines.

Racism means treating groups as unequal on the basis of supposed racial differences. Nazi beliefs about racial superiority were false. Their use in state policy helped justify persecution and conquest. National strength was presented through military power and territorial expansion.

What changed under the dictators?

Mussolini became Italy's Prime Minister in 1922. Hitler became Germany's Chancellor, or head of government, in 1933. Their regimes suppressed opposition and weakened or destroyed democratic restraints. Both glorified military strength and sought expansion beyond their existing national boundaries.

The Great Depression, the severe worldwide economic crisis beginning in 1929, added to unemployment and insecurity. Such conditions helped extremist appeals in Germany. Economic distress explains part of the setting, while the dictators' policies explain how that setting increased international danger.

How did ideas lead to action?

Italy invaded Abyssinia, now called Ethiopia, in 1935. Germany rebuilt its armed strength and sent troops into the Rhineland in 1936. The Rhineland was a German region where the peace arrangements had prohibited German military deployment; sending troops there challenged those restrictions.

These actions matter because military strength was used both to challenge peace restrictions and to conquer foreign territory. Suppression of opposition made governments less accountable at home, while expansion threatened other states abroad. The connection between dictatorship and war therefore involves both concentrated power and the uses made of it.

Note: Fascism and Nazism shared dictatorship, aggressive nationalism and militarism, meaning the emphasis on military power. They were not identical ideologies: racist doctrines occupied a central place in Nazism.

Why did the policy of appeasement fail to preserve peace?

Appeasement means making concessions to an aggressive power in the hope of avoiding war. A concession is something yielded in negotiation. Britain and France followed this approach towards Hitler during the years before the Second World War.

Why were concessions made?

The suffering of the First World War encouraged a strong wish to avoid another conflict. Some British and French leaders also regarded parts of the Versailles settlement as excessively harsh. They hoped that meeting certain German demands would reduce tension and preserve peace.

This policy depended on the expectation that the concessions would satisfy Hitler. His expansionist ambitions, however, went beyond the correction of particular grievances. Each successful challenge increased the danger that further demands would be backed by force.

What happened at Munich?

In 1938 Germany annexed Austria, meaning it incorporated Austria into its territory. Later that year, the Munich Agreement allowed Germany to take the Sudetenland, a region of Czechoslovakia with many German-speaking inhabitants. Britain and France accepted this concession in the hope of preventing war.

Germany occupied the Czech lands in March 1939. This showed that Hitler's aims extended beyond bringing German-speaking people into Germany. The invasion of Poland in September 1939 then demonstrated that appeasement had failed to secure a lasting peace.

The central causal link is that concessions did not stop expansion. They permitted Germany to improve its position while its leadership continued to make demands. Distinguish the intention of appeasement, avoiding war, from its result, failure to restrain the aggressor.

Appeasement was a policy followed by particular governments. It should also be distinguished from the failure of the League of Nations, which concerned the effectiveness of an international organisation and its members' willingness to act together.

How did Japanese expansion in China contribute to the wider conflict?

Imperialism is the extension of a state's power over other territories and peoples. Japan's expansion had developed before the 1930s. It defeated China in 1894 to 1895 and Russia in 1904 to 1905, and made Korea a colony in 1910.

These earlier developments provide background to Japan's later drive for a larger empire. A colony is a territory controlled by another country. The strengthening of Japan's military and expansion of its colonial empire were connected with fear of domination by Western powers.

What happened in 1931 and 1937?

Japan invaded Manchuria, a region in north-eastern China, in 1931. Its invasion of China widened in 1937. These events show that major aggression in Asia preceded the outbreak of the European war in September 1939.

Japanese military leaders sought territory, resources and greater regional influence. The prolonged war weakened China. Japan's attempt to extend its empire also brought it into increasing conflict with powers that opposed its expansion.

How did expansion affect Japanese society?

During the 1930s and 1940s, state-centred nationalism accompanied wars in China and other parts of Asia. Controls on society increased, dissidents faced imprisonment and repression, and patriotic organisations mobilised support for war. Military expansion abroad was accompanied by restrictions at home.

Japan's Asian war merged into the wider Second World War after its attack on the United States at Pearl Harbour. This connection makes the invasion of China a cause within the wider explanation of global conflict, rather than an isolated event unrelated to Europe.

The sequence is therefore important: earlier empire-building formed the background, attacks in China extended the conflict in Asia, and Pearl Harbour brought the United States directly into war with Japan. Japan's imperial project ended in defeat by the Allies.

Why did the League of Nations fail to prevent aggression?

The League of Nations was an international organisation established after the First World War to promote peace. It began work in 1920. Its central difficulty was translating agreement about peace into effective joint action when powerful states used force.

What was collective security?

Collective security means countries acting together to resist aggression and protect peace. It depends on cooperation: members must be willing to support decisions and bear the costs of enforcing them. Condemnation without effective action gives an aggressor little reason to stop.

The League lacked armed forces of its own and depended on its members. The United States did not join it. Major powers were often unwilling to risk war or sacrifice their own interests to enforce collective decisions against aggressors.

Which crises exposed its weakness?

Japan's invasion of Manchuria in 1931 exposed the League's inability to reverse aggression. Japan left the League in 1933. Italy's invasion of Abyssinia in 1935 provided another test; the League's response failed to stop Italian conquest.

Sanctions are restrictions imposed to pressure a state to change its conduct. Restrictions against Italy proved insufficient. The failure was therefore more than an absence of discussion: measures taken did not produce the intended restraint on expansion.

The League had some initial successes, but it could not prevent the Second World War. Retaining that distinction matters. Saying that it never achieved anything would erase its earlier work; saying it maintained peace would overlook the failure that defines this part of its history.

Its weakness encouraged aggressors by showing the limits of international resistance. Together with appeasement, it helped create conditions in which expansion could continue. The failure of peacekeeping arrangements was a contributing cause, while invasions were the direct actions through which war spread.

How did Hitler's invasion of Poland trigger war in Europe?

The immediate cause of a conflict is the event that directly triggers it, while underlying causes develop over a longer period. Germany's invasion of Poland on 1 September 1939 was the immediate cause of the Second World War in Europe.

What happened before the invasion?

Germany and the Soviet Union signed a non-aggression pact in August 1939. Such a pact is an agreement not to attack one another. It reduced Hitler's immediate fear of Soviet opposition as he prepared to attack Poland.

Britain and France had pledged support for Poland. When Germany invaded and did not withdraw, Britain and France declared war on Germany on 3 September 1939. The attack thus widened into a war involving other major European powers.

How do the causes fit together?

1. Resentment of Versailles supplied grievances that Hitler used to demand changes in Europe's settlement.
2. Dictatorship, rearmament and expansionism increased Germany's willingness and capacity to use force.
3. Appeasement and the League's failures did not provide an effective barrier against repeated aggression.
4. The invasion of Poland triggered British and French declarations of war, turning the crisis into open conflict.

The distinction between cause and trigger prevents an incomplete explanation. Poland explains why Britain and France entered war at that moment. The earlier developments explain how Europe reached a position in which the German leadership launched the attack.

Japan's attacks in China remain part of the wider background to the global war. The European starting point in 1939 should not be used to imply that there had been no major fighting in Asia before that year.

What was the significance of Pearl Harbour, Hiroshima and Nagasaki?

Pearl Harbour was a United States naval base in Hawaii. Japan attacked it on 7 December 1941. The United States entered war against Japan following the attack, linking the fighting in the Pacific more closely with the global conflict.

Why did Pearl Harbour matter?

Japan's attack brought the United States directly into the war against it. This was a major change in participation, rather than the beginning of the Second World War as a whole. War in Europe had already begun in 1939, and fighting in China preceded it.

What happened in August 1945?

The United States dropped an atomic bomb on Hiroshima on 6 August 1945 and another on Nagasaki on 9 August 1945. An atomic bomb is a weapon that releases destructive energy through nuclear reactions. Both were Japanese cities.

The bombings caused immense destruction and suffering. Japan announced its surrender on 15 August 1945 and signed the formal surrender on 2 September 1945. A surrender is an acceptance of defeat and the ending of resistance on the terms imposed.

Note: It has been argued that nuclear bombs were dropped on Hiroshima and Nagasaki to shorten the war. But others think the immense destruction and suffering they caused were unnecessary.

The argument about shortening the war must remain an attributed interpretation. It should not become a claim that the bombings were unquestionably necessary. The events, their devastating effects and the debate over justification are different parts of the explanation.

For chronology, associate Pearl Harbour with the entry of the United States in 1941 and Hiroshima and Nagasaki with Japan's defeat in 1945. These events mark different stages of the war and should not be combined into a single episode.

What were the consequences of the defeat of the Axis powers?

The defeat of Germany, Italy and Japan ended the Axis attempt to dominate large parts of Europe and Asia. The war concluded in 1945, but defeat did not occur simultaneously for every Axis country. Events in Europe and Japan followed different sequences.

How did Axis rule collapse?

Mussolini lost power in Italy in 1943, and the Italian government signed an armistice with the Allies that year. An armistice is an agreement to stop fighting. Fighting in Italy continued, so the armistice should not be confused with an immediate end to warfare there.

Germany surrendered in May 1945. Hitler's dictatorship collapsed with German defeat. Japan surrendered later in 1945, bringing its attempt to build a larger colonial empire to an end. Defeat therefore overturned the expansionist projects that had helped produce the conflict.

How did the international balance change?

The United States and the Soviet Union emerged as the leading powers. A superpower is a state with exceptional military, economic and international influence. The Soviet Union became a great power after the war, and its influence extended across much of eastern Europe.

The consequences can be organised under three connected headings: the defeat of the Axis powers, the formation of the United Nations, and the emergence of the Cold War. The first concerns the outcome of fighting; the others concern the organisation and division of the post-war world.

Victory did not remove disagreement among the Allies. Countries that had cooperated against a common enemy differed over political systems, security and influence. Those differences help explain why the end of one war was followed by a prolonged period of rivalry.

How did the United Nations emerge from the war?

The United Nations, abbreviated as UN, is an international organisation created to promote peace and cooperation among states. It was founded in 1945 as the successor to the League of Nations. Its creation reflected the determination to prevent another destructive world war.

What were the main steps towards its formation?

A charter is a document setting out the purposes and basic arrangements of an organisation. The UN Charter should be distinguished from the earlier Atlantic Charter. The earlier declaration of principles contributed to wartime planning; the UN Charter established the new organisation's framework.

What problem was the UN intended to address?

The UN aimed to prevent international conflict and facilitate cooperation. It was founded with the hope of stopping disputes from escalating into war and limiting hostilities if war occurred. It also sought cooperation in social and economic development, since conflicts often arose from its absence.

The organisation is not a world government with unrestricted authority over its members. States created it and must cooperate through it. Its establishment was a major institutional consequence of the war, but its existence did not itself guarantee the disappearance of conflict.

What was the Cold War, and how did NATO and the Warsaw Pact compare?

The Cold War was the prolonged rivalry between the United States and the Soviet Union and their respective allies after the Second World War. It involved political tension, ideological competition, military preparations and struggles for influence without a direct full-scale war between the two superpowers.

Capitalism is an economic system in which private ownership plays a central role. The United States led the capitalist bloc. The Soviet Union led a communist bloc with one-party governments and economies dominated by state ownership and planning. A bloc is a group of aligned countries.

Why did two blocs develop?

The Soviet army's defeat of fascist forces in eastern Europe was followed by Soviet control over those countries. Their political and economic systems were modelled on the USSR. Wartime cooperation gave way to rivalry as the leading powers sought security and influence.

An alliance is an agreement between states to cooperate for common purposes. A military alliance organises cooperation in defence. The two major Cold War alliances expressed the division between the US-led Western bloc and the Soviet-led Eastern bloc.

NATO is an abbreviation of its full name; Warsaw Pact is the name of an alliance, not an abbreviation requiring expansion. Both belong to the post-war rivalry. Neither should be listed as one of the opposing alliances fighting the Second World War.

Cold War does not mean that the world experienced no wars. It identifies the character of the central US-Soviet relationship. The creation of the UN and the formation of rival blocs therefore represent simultaneous efforts at cooperation and patterns of international division.

What timeline connects the causes, major events and consequences?

A timeline places developments in chronological order, meaning the order in which they happened. This sequence distinguishes the peace settlement, the expansion of aggressive powers, the outbreak and widening of war, and the arrangements that followed victory.

Chronology helps organise causes but does not prove causation by itself. A full explanation must also show the connection, such as how a concession failed to restrain expansion or how an invasion brought another country into the fighting.

How do historical sources distinguish agreements, intentions and outcomes?

Historical sources are records or other evidence used to investigate the past. Treaties and declarations are useful for identifying what governments formally accepted. Their existence alone does not prove that their purposes were achieved or that every affected population agreed with them.

What can the agreements reveal?

The Treaty of Versailles of 1919 records the settlement imposed on Germany. Studying its terms explains the basis of grievances about territory, military restrictions and reparations. Explaining how Hitler used those grievances requires a further link between the settlement and later political action.

The Munich Agreement of 1938 illustrates a concession made in the hope of avoiding war. Germany's occupation of the Czech lands in 1939 supplies evidence about the failure of that hope. An agreement's intended purpose and its subsequent outcome must be examined separately.

The UN Charter of 1945 sets out the framework of the new international organisation. It is evidence of a commitment to cooperation after the war. It does not demonstrate that international rivalry disappeared, as the emergence of the Cold War makes clear.

How should interpretations be handled?

An interpretation is an explanation of evidence and its significance. The argument that atomic bombing shortened the war and the view that its destruction was unnecessary are interpretations to distinguish from the dates and locations of the attacks. Keep a debated justification separate from an established event.

Glossary

• Axis powers — The wartime group whose principal members were Germany, Italy and Japan.
• Allies — Countries fighting the Axis powers, including Britain, France, China, the Soviet Union and the United States.
• Reparations — Compensation required from a defeated country for damage caused during a war.
• Rearmament — The rebuilding or increase of a country's armed forces and military equipment.
• Fascism — An authoritarian ideology associated with Mussolini, stressing state supremacy, obedience to a leader and aggressive nationalism.
• Nazism — Hitler's ideology combining dictatorship, aggressive expansion and false doctrines of racial superiority.
• Appeasement — Making concessions to an aggressive power in the hope of avoiding war.
• Collective security — Cooperation among countries to resist aggression and protect international peace together.
• Sanctions — Restrictions imposed on a state to pressure it to change its conduct.
• Armistice — An agreement to stop fighting, distinct from a complete political peace settlement.
• United Nations — The international organisation founded in 1945 to promote peace and cooperation among states.
• Cold War — Post-war rivalry between the US-led and Soviet-led blocs without direct full-scale war between the superpowers.
• NATO — North Atlantic Treaty Organisation, the US-led military alliance formed in 1949 for collective defence.
• Warsaw Pact — The Soviet-led military alliance formed in 1955 with allied eastern European states.

Common errors and misconceptions

• Misconception: Versailles was the immediate trigger of war in 1939. Correct: Treaty grievances were an underlying cause; Germany's invasion of Poland was the immediate trigger in Europe.
• Misconception: Appeasement was intended to begin a war. Correct: Its intention was to avoid war through concessions, but it failed to restrain Hitler's expansion.
• Misconception: The League never achieved anything. Correct: Despite some initial successes, it could not prevent the Second World War.
• Misconception: Pearl Harbour began the entire Second World War. Correct: The attack brought the United States into war against Japan in 1941; war in Europe began in 1939.
• Misconception: The atomic bombings were unquestionably necessary. Correct: Their justification is debated: some argue that they shortened the war, while others regard the destruction as unnecessary.
• Misconception: NATO and the Warsaw Pact fought against each other in the Second World War. Correct: They were military alliances formed after that war, during the Cold War.
• Misconception: Cold War means that there were no wars anywhere. Correct: It describes superpower rivalry without direct full-scale war between the United States and Soviet Union.

Exam-style questions with model answers

Q1. Germany invaded Poland on 1 September 1939; Britain and France declared war on Germany on 3 September. Identify the immediate trigger and explain how the conflict widened. [2 marks]

1. Germany's invasion of Poland on 1 September 1939 was the immediate trigger of the war in Europe.
2. British and French declarations of war on Germany on 3 September widened the conflict to include those powers.

Q2. Versailles imposed territorial losses, military restrictions and reparations on Germany. Hitler appealed to resentment of these terms as humiliating and promised to restore territory and military strength. Explain three ways the settlement contributed to support for his policies. Reparations means compensation for war damage. [3 marks]

1. Territorial losses created resentment that Hitler could use to support demands for changes to Germany's boundaries and possessions.
2. Military restrictions supplied a grievance that helped him appeal for the rebuilding of German armed strength.
3. Reparations added resentment about the peace terms, strengthening his appeal to people who regarded the settlement as humiliating.

Q3. Britain and France accepted Germany's acquisition of the Sudetenland through the Munich Agreement in 1938, hoping to avoid war. Germany occupied the Czech lands in March 1939 and invaded Poland in September. Explain appeasement, its intention, its method and the evidence of failure. [4 marks]

1. Appeasement means making concessions to an aggressive power in an attempt to reduce tension and prevent war.
2. Britain and France intended the Munich settlement to avoid armed conflict by meeting a German demand.
3. The method was a territorial concession: Germany was allowed to acquire the Sudetenland in 1938.
4. German occupation of the Czech lands and invasion of Poland in 1939 showed that the concession had not ended expansion.

Q4. The League lacked armed forces of its own and depended on members; the United States did not join. Japan invaded Manchuria in 1931, and sanctions failed to stop Italy's conquest of Abyssinia after its 1935 invasion. Explain four weaknesses or failures of collective security shown by this evidence. Sanctions are pressure through restrictions. [4 marks]

1. Without its own armed forces, the League depended on member governments to provide the means of enforcing decisions.
2. The absence of the United States limited participation by a major power in the collective system.
3. The invasion of Manchuria showed that membership in an international peace system did not itself prevent aggression.
4. The failure of sanctions to stop Italian conquest showed that the pressure applied was insufficient to secure restraint.

Q5. Japan attacked Pearl Harbour on 7 December 1941, bringing the United States into war against it. The United States dropped atomic bombs on Hiroshima on 6 August 1945 and Nagasaki on 9 August. Some argue that the bombs shortened the war; others regard their immense destruction and suffering as unnecessary. Present five distinct points explaining the events and the debate. [5 marks]

1. The Pearl Harbour attack occurred in December 1941 and brought the United States directly into war against Japan, changing the scale of participation.
2. Hiroshima was attacked on 6 August 1945, when the United States used an atomic bomb against the Japanese city.
3. Nagasaki was attacked with another atomic bomb on 9 August 1945, three days after the bombing of Hiroshima.
4. One interpretation argues that the atomic bombings shortened the war; this is a claim about their purpose and effect.
5. The opposing interpretation regards the immense destruction and suffering as unnecessary, so necessity should not be presented as an uncontested conclusion.

Q6. Germany and Japan surrendered in 1945, ending their wartime expansionist projects. The UN was founded that year to promote peace and cooperation. The United States and Soviet Union became leading powers, but their wartime cooperation gave way to rivalry. Explain the three named consequences: Axis defeat, UN formation and Cold War. [3 marks]

1. Axis defeat ended the expansionist projects of the defeated powers, with Germany and Japan surrendering in 1945.
2. Formation of the United Nations created an international organisation through which states could pursue peace and cooperation after the war.
3. The Cold War developed as cooperation between the leading United States and Soviet Union gave way to rivalry and competing influence.

Q7. NATO, the North Atlantic Treaty Organisation, was formed in 1949 under US leadership. The Warsaw Pact was formed in 1955 under Soviet leadership. Both were military alliances for collective defence in opposing Cold War blocs. Give four comparison points using the information provided. [4 marks]

1. The alliances differed in name: NATO abbreviates North Atlantic Treaty Organisation, whereas Warsaw Pact is the other alliance's name.
2. They differed in formation year: NATO was formed in 1949, while the Warsaw Pact followed in 1955.
3. They had different leaders: the United States led NATO, and the Soviet Union led the Warsaw Pact.
4. Both organised collective defence, but they belonged to opposing blocs within the Cold War division.

Key takeaways

• Versailles grievances helped Hitler's appeal, but dictatorship, expansionism and failures of restraint connected those grievances with another war.
• Appeasement sought peace through concessions, yet the Munich settlement did not prevent further German expansion.
• Japan's invasions in China preceded the European war and formed part of the wider development of global conflict.
• Germany invaded Poland on 1 September 1939; British and French declarations of war followed on 3 September.
• Pearl Harbour brought the United States into war against Japan; Hiroshima and Nagasaki belong to the final stage in 1945.
• The justification for atomic bombing remains debated; preserve the distinction between established events and arguments about necessity.
• The defeat of the Axis powers, formation of the United Nations and emergence of the Cold War reshaped international relations.
• NATO and the Warsaw Pact were opposing post-war military alliances, associated respectively with US and Soviet leadership.

Test yourself

What is the difference between an underlying cause and an immediate trigger?

An underlying cause develops over time; an immediate trigger is the event that directly brings about the outbreak of conflict.

What did appeasement seek to achieve?

It sought to avoid war by making concessions to an aggressive power.

Which two invasions exposed the League's inability to restrain Japan and Italy?

Japan's invasion of Manchuria in 1931 and Italy's invasion of Abyssinia in 1935 exposed that weakness.

What happened on 1 and 3 September 1939?

Germany invaded Poland on 1 September; Britain and France declared war on Germany on 3 September.

How should the claim that atomic bombs were necessary be handled?

Treat it as a debated interpretation: some argue that the bombs shortened the war, while others regard their destruction and suffering as unnecessary.

When was the United Nations founded, and why?

It was founded on 24 October 1945 to promote international peace and cooperation among states.

What does NATO stand for, and which power led it?

NATO stands for North Atlantic Treaty Organisation; the United States led this military alliance.

What was the Warsaw Pact?

It was a Soviet-led military alliance formed in 1955 with allied eastern European states.