World War II led to lots of serious hunger crises, which caused a large number of casualties. It could potentially have long-term effects on adult health and socioeconomic status.

For instance, since the beginning of the German invasion, the nutritional condition of the non-German people in Poland has been terrible. The average consumption of the Polish people in 1941 was roughly 930 calories. The Warsaw Ghettos, on the other hand, were among the worst conditions, with average food rations of only 186 calories each day in 1941. In Greece, a catastrophic famine killed 100,000 to 200,000 inhabitants.

From 1944 to 1945, the Netherlands experienced a terrible hunger crisis as a result of food restrictions and severe winters. Furthermore, the battle cut off the food supply from occupied nations. In 1945, the Office of Military Government for Germany established a target of 1550 calories each day in the US occupation zone, which was regularly not achieved. In some locations, the average daily calorie consumption was about 700. During this time, adult mortality rates grew by four, while infant death rates rose by ten.

The Second World War can be described as a terrible catastrophe for humankind. In 1939, there were approximately 2 billion people on the earth. According to the most conservative figures, between 62 and 78 million people would die as a result of World War II, making up more than 3% of the global population. Around 24 million people were injured or disabled after the war.

While previous wars have caused civilian deaths, World War 2 disproportionately impacted civilians. Furthermore, civilians accounted for about half of all World War II European casualties. In addition to civilian deaths, the Nazi regime killed between 9.8 and 10.4 million people for ideological or racial causes.

However, whether as war dead, lives lost, or Holocaust victims, deaths from the battle were unequally distributed among nations. Germany and Poland were the European nations that were most affected in terms of fatalities. More than 400,000 Americans were killed in the European and Asian theaters combined. Most of these people were servicemen. Likewise, the total number of deaths in the UK is estimated to be roughly 450,000, with civilians making up 15% of the total. The atomic bombs launched by the United States on Hiroshima and Nagasaki killed 160,000 people and demolished the entire city.

Decolonization is the opposite of colonialism. Decolonization is the process by which colonies gain independence from the colonizing country. Decolonization was steady and peaceful in certain British colonies, which were mostly occupied by expatriates, but violent in others, where native rebellions were driven by nationalism.

Following World War II, European nations often lacked the financial and political assistance to defeat faraway rebellions; they also faced pressure from the new superpowers, the United States and the Soviet Union, both of which had taken anti-colonialist positions. Korea was liberated in 1945 as a result of Japan's defeat in the war. In 1946, the United States surrendered the Philippines. Britain withdrew India in 1947, Palestine in 1948, and Egypt in 1956; it left Africa in the 1950s and 1960s, numerous island protectorates in the 1970s and 1980s, and Hong Kong in 1997.

The French left Vietnam in 1954 and their North African territories by 1962. In the 1970s, Portugal gave up its African colonies, and Macau was handed to the Chinese. Similarly, Sub-Saharan African countries earned freedom despite being quite slow. Furthermore, the People's Republic of China grew to power in Southeast Asia. Likewise, the Communist Party of China won the Chinese Civil War in 1949.

Another major effect of World War II that should be mentioned is the Marshall Plan. It was named after the US Secretary of State, George C. Marshall, who proposed the plan.

The Marshall Plan (also known as the European Recovery Program, ERP) was an initiative of America in the year of 1948 to offer international assistance to Western Europe. Following World War II, the United States transferred about $13 billion (equal to around $115 billion in 2021) in economic recovery projects to Western European countries. It replaced an earlier Morgenthau Plan plan and ran for four years, commencing on April 3, 1948.

One of the significant aims of the Marshall Plan was to reconstruct cities, industries, and infrastructure that had been severely devastated during the war. The proposal also called for the elimination of tariffs between European neighbors and the promotion of business transactions among those nations and the United States. Besides economic recovery, the Marshall Plan also aimed to prevent the spread of communism on the European continent.

The Molotov Plan was a mechanism devised by the Soviet Union in 1947 to offer assistance for the reconstruction of Eastern European nations that were allied with the Soviet Union politically and economically.

In the Soviet Union, it was initially named the "Brother Plan." It can be considered as the Soviet Union's equivalent of the Marshall Plan, which the Eastern European nations would be unable to join due to political reasons unless they left the Soviet sphere of influence. Vyacheslav Molotov, the Soviet foreign minister, refused the Marshall Plan (1947), instead suggesting the Molotov Plan, a Soviet-sponsored economic association that was subsequently developed to become the Comecon (Council for Mutual Economic Assistance).

The Molotov Plan represented the Soviet Union's rejection to recognize or permit any of their satellite states to receive Marshall Plan aid. This is because they believed that the Marshall Plan was an effort to diminish Soviet interest in their satellite states through the conditions enforced and by trying to put beneficiary countries into being financially dependent on the United States. Actually, the Marshall Plan also aimed to stop Communism from developing. The plan called for a system of bilateral trade agreements, as well as the formation of Comecon, an economic union of socialist countries.

Nations were in ruins when World War II came to a close in 1945, and the world desired peace. From April 25 to June 26, 1945, representatives from 50 nations assembled in San Francisco, California, for the United Nations Conference on International Organization. They spent the next two months drafting and signing the UN Charter, which established a new international organization, the United Nations.

The United Nations aims to deter another world war like the one that has already occurred. On October 24, 1945, four months after the San Francisco Conference, the United Nations was formally established. China, France, the Soviet Union, the United Kingdom, the United States, and a number of other signatory countries approved its charter.

More than 75 years later, the United Nations is still striving to keep global peace and safety, provide humanitarian aid to those in need, promote human rights, and enforce international law.

At the same time, the United Nations is undertaking new missions that its founders did not envision for it in 1945. The United Nations has established the 2030 Sustainable Development Goals in order to ensure a better and more sustainable future for all of us. The United Nations has also agreed to take climate action to minimize global warming.