World War II – Summary, Causes, Consequences, Countries


We explain what the Second World War was and the causes of this conflict. In addition, its consequences and the participating countries.

Second World War
The Second World War took place between the years 1939 and 1945.

What was the Second World War?

World War II was an armed conflict that took place between the years 1939 and 1945, and that directly or indirectly involved most of the military and economic powers of the time, as well as numerous Third World countries.

It is considered the most dramatic war in contemporary history, due to the number of people involved, the enormous territorial dimensions of the conflict, the amount of military weapons used and the heartbreaking historical consequences for humanity.

The Second World War It took place mainly in three different settings: the European, Asian and African continents. In them, the troops of the two opposing sides, known as the Allied Countries and the Axis Powers, faced each other, as well as the countries involved voluntarily or by force in a conflict that did not distinguish between military forces and the civilian population.

In the context of this war, highly traumatic events occurred for human civilization, such as the mass deaths in extermination and forced labor camps (in particular of citizens of the Jewish ethnic group, which was called the Holocaust), or the use for the first time in history of nuclear weapons of mass destruction on a civilian population (the Japanese cities of Hiroshima and Nagasaki).

Causes of World War II

Second World War
The German invasion of Poland was one of the causes of World War II.

Like all war, World War II was due to varied and complex reasons, which can be summarized as:

  • The terms of the Treaty of Versailles. The surrender of Germany and its allies at the end of World War I imposed on them a highly oppressive unconditional surrender treaty, which prevented the war-torn nation from having an army again, wrested control of its African colonies, and gave it away. it imposed an unpayable debt with the victorious countries.
  • The rise of fascism. Adolf Hitler in Germany (Nazism) and Benito Musolini in Italy (fascism), mainly, took advantage of popular discontent and built extremist nationalist movements, seeking to recover national glories through the militarization of broad social sectors, the establishment of totalitarianism and the expansion of the national borders.
  • Sino-Japanese tensions. After the First Sino-Japanese War (1894-1895), Japan had become an imperial power that did not look favorably on China and the Soviet Union. Taking advantage of the weakness in which the Civil War between communists and republicans had left China in 1932, Japan initiated a Second Sino-Japanese War and occupied Manchuria, later expanding throughout the Asia Minor until it was faced by the United States.
  • The German invasion of Poland. Germany began its territorial expansion by taking Austria and part of Czechoslovakia, without major conflicts. When in 1939 Hitler established a pact with the USSR to divide up the Polish territory and proceeded to invade it, the western European nations declared war on him, starting the conflict as such.

Consequences of World War II

Second World War
World War II caused between 55 and 70 million deaths.

The consequences of the Second World War were particularly dire. Some of them were:

  • Almost total devastation of Europe. Extensive and devastating aerial bombardments of the main European cities took place, first when the Germans conquered the continent and then when the allies liberated it, which resulted in their almost total destruction. This later required large economic investments for its gradual reconstruction, such as the so-called Marshall Plan proposed by the United States.
  • Start of a bipolar world. The European powers, both Allied and Axis, were, at the end of the conflict, so economically and politically weakened that the conduct of world politics passed to the two new superpowers: the United States and the Soviet Union, thus initiating the so-called Cold War. .
  • Germany Division. Once Germany was defeated, its territory came under the control of the allied countries and the USSR, for which the country was divided into two completely different nations: the German Federal Republic, with a capitalist system and under North American control, and the German Democratic Republic. , with a communist system and under Soviet administration. Germany would unify again in 1991, after the fall of the Berlin Wall.
  • Emergence of new technologies. Technologies today common such as television, computers, sonar, jet flight or atomic energy owe their discovery to this bloody war.
  • Decolonization. Europe’s loss of political and economic power led to the loss of control of its colonies in the Third World, thus allowing numerous independence processes.
  • The death of between 55 and 70 million people. Counting military and civilians, indistinctly, millions of which did so in subhuman conditions in concentration and extermination camps.

Participating countries

The two opposing sides were:

  • The powers of the axis. Led by Nazi Germany, Fascist Italy, and Imperial Japan, along with their partners from Bulgaria, Hungary, Romania, and co-belligerent states such as Finland, Thailand, Iran, and Iraq.
  • Allied countries. Made up of France, Great Britain, the United States and the Soviet Union, as well as Poland, China, Norway, Denmark, Belgium, Luxembourg, the Netherlands, Greece, Yugoslavia, Canada, New Zealand, South Africa, Australia and, later, some countries of minority participation but diplomatic support to the allies.