World War I: There is only a capitalist system in the world.
World War II: In addition to the capitalist system, there was a socialist state, the Soviet Union. Imperialism such as German,Italian,Japanese fascism and Britain, France, and the United States all have contradictions with the Soviet Union, while German, Italian, and Japanese fascists and Britain, France, and the United States have sharp contradictions. After the "First World War", in order to gain the support and connivance of Britain, France and the United States for its aggression and expansion, Hitler used the banner of "anti-Soviet and anti-communist" to achieve it. Later, the aggression of the fascist countries against Ethiopia, Poland, and so on greatly increased the economic and military strength of the fascist countries. Britain, France, the United States and other major powers first missed the opportunity, and then suffered their own consequences, and had to ally with the Soviet Union in World War II to oppose the fascist forces.
1- The outbreak of the First World War was fundamentally caused by the uneven development of capitalist political and economic development, the struggle of old and new imperialism for world hegemony and the re-division of the colonies. The imbalance in the development of capitalist political and economic development intensified with the transition to the imperialist stage, and the position of industrialized production in several major capitalist countries in the world changed: the old capitalist countries of Britain and France retreated to the third and fourth places, and the emerging United States and Germany leapt to the first and second places in the world. The imbalance in economic development changed the balance of power between the imperialist countries, resulting in a decline in power and the loss of the colonies they occupied. At the end of the 19th century and the beginning of the 20th century, the world had been basically divided, so in Europe, a situation was formed in which the emerging Germany competed with the old capitalist countries Britain and France for hegemony and redivided the world.
With the intensification of contradictions between imperialist countries, three basic contradictions have been formed in Europe, namely, the Franco-German contradiction, the Russian-Austrian contradiction and the Anglo-German contradiction. Around these three basic contradictions, the three major military groups (Germany, Italy, Austria) and the Triple Entente (Britain, France, and Russia) were formed, and the confrontation between the two major military groups and fierce competition accelerated the tension in Europe, which eventually led to the outbreak of the First World War.
On June 28, 1914, the Crown Prince of Austria-Hungary was stabbed in Sarajevo, which became the trigger for world war I.
2- The outbreak of the Second World War was also due to the uneven development of capitalist political and economic development. The economic crisis aggravated the contradictions between the imperialist countries, and from 1929 to 1933, under the influence and blow of the capitalist world economic crisis, Germany, Italy and Japan established a fascist dictatorship in an attempt to get rid of the economic crisis by means of crazy expansion, and the two sources of war in Europe and Asia were finally formed. European source: In 1923, the Nazi Party became the largest party in the Reichstag, and in 1933, Hitler became chancellor of Germany, seized state power, imposed a reign of terror at home, actively expanded externally, and formed the source of the world war in Europe. Sources of Asia: Hirota Hirohito, who was controlled by the fascists of the military department, came to power to form a cabinet, banned workers' strikes internally, restricted the people's freedom of speech, association, press, and the press, stepped up the expansion of armaments war abroad, formulated a basic national policy of aggression and expansion, actively prepared to expand wars of aggression, and formed the source of a world war in Asia.
The First World War was an imperialist war waged by the two major imperialist military blocs for markets and raw material production areas and for the interests of overseas colonies.
The Second World War was a war against fascism among the peoples of the world. During the war, countries of different social systems worked closely together to establish anti-fascist alliances, jointly waged anti-fascist struggles, and won the final victory.
The Second World War was larger than the war of the First World War, and brought greater human and financial losses to the world.
But both weakened the power of some imperialist countries, and after the war there were national liberation movements and some political systems after the war.
World War I: From 1914 to 1918, which lasted more than four years, more than 30 countries participated in the war, the combat area reached 4 million square kilometers, the armed force reached 70 million, and 1.5 billion people were involved in the war, causing huge material and spiritual losses to mankind, seriously weakening the power of imperialism and colonialism, destroying the Russian, German, Austro-Hungarian and other empires, and the feudal Ottoman Empire was also dissolved. Imperialist countries such as Britain, France and Italy were weakened. At the end of the war, the Russian proletariat opened a weak link in the chain of imperialism and won the victory of the socialist revolution. In the early post-war period, the proletarian revolutionary movement in the capitalist countries and the national liberation movements in Asia, Africa and Latin America showed a new situation of upsurge.
World War II: All over the world, a total of 61 countries participated in the war, the combat area of up to 22 million square kilometers, the armed force reached 110 million, 80% of the world's population, that is, a total of 1.7 billion people were involved in the war, a large amount of wealth was lost, is the largest war in human history so far, has a huge impact. The war destroyed fascism, educated peoples and the idea of peace and progress became increasingly popular. The Great War dealt a heavy blow to international imperialism and promoted the vigorous development of the national liberation movement. The war completely crushed German, Italian and Japanese imperialism, weakened the imperialist countries other than the United States, and seriously shook imperialist colonial rule in the world. The strength of the colonial and semi-colonial peoples was strengthened during the war, creating favorable conditions for the national liberation movement. The war has also contributed to the development and growth of the international community. The international status of the Soviet Union was greatly enhanced, becoming one of the most powerful countries in the world; many countries in the world established people's democratic power and embarked on the road of socialism, which exceeded the scope of one country. At the same time, the Second World War objectively promoted the rapid development of science and technology and promoted the progress of human civilization.
However, in the two great wars, mankind, on an unprecedented scale and speed, threw advanced science and technology and creative inventions into the war, and threw the human and material resources of the entire nation and the whole country into the war. The war has caused an uncountable consumption of manpower and material resources and has brought deep disasters to the people of the whole world. However, the impact of the great wars did not stop there, they had an extremely far-reaching impact on the course of human historical development, on the world economic and political pattern, and on people's ideological concepts.
Looking back at the two world wars and revisiting the history of blood and fire can not only enrich historical knowledge, but also take history as a mirror and reflect in depth on the survival and development of mankind, war and peace.