GLOBAL CHANGES SINCE 1945

1. Introduction: A world transformed after 1945

The year 1945 represents a fundamental turning point in world history. It marked the end of World War II, a conflict that caused tens of millions of deaths, destroyed entire cities and left European economies in ruins. However, the end of the war did not bring lasting peace. Instead, it opened the door to a new era defined by profound political, economic, social and technological changes. The old European powers (Great Britain, France, Germany) emerged weakened, while two new superpowers arose: the United States and the Soviet Union. These two nations represented two opposing ideological models: capitalism and communism. Their rivalry would shape international relations for the next five decades in what became known as the Cold War. At the same time, the world witnessed the rapid process of decolonisation, as dozens of countries in Asia, Africa and the Middle East achieved their independence from the old European empires. Economically, the post-war period saw an unprecedented recovery followed by crisis and globalisation. Technologically, humanity reached the Moon, developed computers and the internet, and made enormous advances in medicine. Socially, women's rights, civil rights and youth culture transformed societies. This theme will explore all these global changes since 1945 in a detailed and structured way.

2. The Cold War: The division of the world into two blocs

The Cold War began almost immediately after the end of World War II. Although the United States and the Soviet Union had been allies against Nazi Germany, their alliance broke down once the common enemy was defeated. The fundamental reason was ideological: the United States defended capitalism (private property, free market, democracy, individual freedoms), while the Soviet Union defended communism (state property, planned economy, one-party system). Each superpower believed its system was the best for humanity and wanted to spread it to other parts of the world. Although it was called a "war", there were no direct battles between American and Soviet soldiers. Instead, the conflict took the form of an arms race, space race, espionage, propaganda and proxy wars (indirect wars in other countries). Both sides accumulated enormous arsenals of nuclear weapons, creating a state of constant fear known as Mutually Assured Destruction (MAD), which paradoxically prevented a direct war because any confrontation could have led to a nuclear holocaust.

One of the first major events was the division of Germany. After the war, Germany was divided into West Germany (allied with the US) and East Germany (controlled by the USSR). The city of Berlin, located inside East Germany, was also divided. In 1961, the communist government built the Berlin Wall, a concrete barrier that physically separated the two parts of the city and became the most powerful symbol of the division of the world into two opposing blocs. The wall prevented East Germans from fleeing to the West, and hundreds of people died trying to cross it. Another key moment was the Cuban Missile Crisis of 1962. The Soviet Union had placed nuclear missiles on Cuba, very close to the US coast. When American spy planes discovered the missiles, the world held its breath for thirteen days. President John F. Kennedy ordered a naval blockade and demanded the removal of the missiles. Fortunately, the crisis was resolved peacefully when Soviet leader Nikita Khrushchev agreed to remove the missiles in exchange for a US promise not to invade Cuba and to remove its missiles from Turkey. The Cuban Missile Crisis taught world leaders the importance of communication and negotiation to avoid nuclear disaster.

The Cold War also had a strong impact on other regions. In Vietnam, the United States fought a long and bloody war to prevent the country from falling under communist control. In Korea, the peninsula was divided into a communist north and a capitalist south after a war that ended in a stalemate. In Afghanistan, the Soviet Union invaded in 1979 to support a communist government, but ended up trapped in a long and costly war that contributed to the eventual collapse of the USSR. The Cold War finally came to an end between 1989 and 1991. The Soviet Union was suffering from severe economic problems, and its leader, Mikhail Gorbachev, introduced two new policies: perestroika (economic restructuring) and glasnost (political openness). These reforms, however, unleashed forces that Gorbachev could not control. In 1989, the countries of Eastern Europe began to rebel against their communist governments. The most symbolic moment occurred on November 9, 1989, when the Berlin Wall was opened and people from both sides crossed freely for the first time in 28 years. Thousands of Germans celebrated the fall of the wall, and soon afterwards Germany was reunified. In 1991, the Soviet Union was dissolved, and its fifteen republics became independent countries. The Cold War was over.

3. Decolonisation: The end of the european empires

At the same time as the Cold War was developing, another great transformation was taking place: decolonisation, that is, the end of the old European colonial empires. Before World War II, Great Britain, France, Belgium, the Netherlands, Portugal and Spain controlled vast territories in Africa and Asia. However, the war had considerably weakened these European powers. They did not have the economic resources or military strength to maintain control over their colonies, especially when faced with increasingly powerful independence movements. Several causes explain decolonisation. First, the war had created a moral and political climate against colonialism. The Atlantic Charter (1941) stated that all peoples had the right to choose their own government. Second, the new superpowers (USA and USSR) were both opposed to the old European empires, although for different reasons. Third, the colonies themselves had developed strong nationalist movements led by educated local elites determined to achieve independence.

The process of decolonisation began in Asia. The first great event was the independence of India in 1947. India had been the "jewel in the crown" of the British Empire for almost two centuries. The independence movement was led by Mahatma Gandhi, who advocated non-violent resistance and civil disobedience. Finally, the British granted independence, but the process was accompanied by the partition of the subcontinent into two separate countries: India (Hindu majority) and Pakistan (Muslim majority). The partition caused one of the largest mass migrations in history, with millions of people crossing the new borders, and there were terrible massacres between Hindus, Muslims and Sikhs. Gandhi himself was assassinated in 1948 by a Hindu extremist. In Southeast Asia, Indonesia declared independence from the Netherlands in 1945. French Indochina (Vietnam, Laos, Cambodia) also fought for its independence. In Vietnam, the communist leader Ho Chi Minh declared independence in 1945, but the French refused to accept it and began a long war that ended with the French defeat at Dien Bien Phu in 1954. The Geneva Accords of 1954 divided Vietnam into a communist north and a capitalist south, a division that would later lead to the Vietnam War.

Decolonisation in Africa began somewhat later. In the 1950s and 1960s, dozens of African countries achieved their independence. The year 1960 is known as the "Year of Africa" because 17 African countries became independent, most of them from France. However, the process was not always peaceful. In Algeria, the French fought a brutal war against the independence movement from 1954 to 1962. The Algerian War was characterised by torture, terrorist attacks, and a massive exodus of French settlers. In the Belgian Congo, independence in 1960 was followed by a period of chaos, civil war and foreign intervention. The Portuguese colonies (Angola, Mozambique) did not achieve independence until the 1970s, after a long guerrilla war. Decolonisation had both positive and negative consequences. On the positive side, it meant the end of colonial domination and the possibility for new countries to govern themselves. On the negative side, the borders had been drawn by the European powers without considering ethnic, linguistic and religious realities, which caused many conflicts. In addition, the new countries were often very poor and lacked infrastructure, education and a trained civil service. Many fell into the hands of dictators or were caught up in the Cold War rivalry, becoming proxy battlegrounds between the US and the USSR.

4. Economic changes: From reconstruction to Globalisation

The global economy also underwent profound changes after 1945. At the end of World War II, Europe and Japan lay in ruins. However, the following decades saw an unprecedented economic recovery, known as the Golden Age of Capitalism (1950-1973). During this period, Western Europe, the United States and Japan experienced sustained economic growth, low unemployment and a significant rise in living standards. Several factors contributed to this growth. First, the United States provided massive economic aid to Europe through the Marshall Plan, which helped rebuild factories, roads, ports and railways. Second, there was a great increase in trade between countries, encouraged by the creation of new international institutions such as the International Monetary Fund, the World Bank and GATT. Third, technological advances made possible the mass production of new consumer goods, such as cars, washing machines, refrigerators and televisions. During these decades, the Welfare State was consolidated in many Western European countries. The Welfare State is a system in which the government takes responsibility for the well-being of its citizens by providing public services such as free healthcare, free education, unemployment benefits, old-age pensions and social housing. The goal was to reduce poverty and inequality and to create a more just and stable society. The combination of economic growth and social policies allowed the creation of a large middle class, which enjoyed a standard of living unimaginable for their grandparents.

However, the Golden Age came to an end in 1973 with the oil crisis. That year, the Arab countries of OPEC decided to stop selling oil to the countries that had supported Israel in the Yom Kippur War. The price of oil quadrupled in a few months, and Western economies, which depended heavily on oil, went into recession. Factories closed, unemployment rose sharply and inflation spiralled out of control. The 1970s were a decade of economic crisis, social unrest and political instability. The old certainties of the post-war period collapsed, and a new economic model emerged, based on privatisation, deregulation and the reduction of the Welfare State. This new model, known as neoliberalism, was promoted by leaders such as Margaret Thatcher in Great Britain and Ronald Reagan in the United States. Since the 1980s, globalisation has accelerated. Globalisation is the process of increasing economic, political and cultural integration between the countries of the world. It has been driven by several factors: the reduction of trade barriers, the revolution in transport (container ships, air freight) and the revolution in communications (the internet, mobile phones). Globalisation has allowed companies to produce goods in countries where labour is cheap and to sell them in markets all over the world. It has brought great benefits, such as lower prices for consumers and the lifting of millions of people out of poverty in countries such as China and India. However, it has also created problems, such as job losses in developed countries, exploitation of workers in developing countries and the growing power of multinational corporations. In addition, the financial crisis of 2008, which began in the United States with the collapse of the housing bubble, showed that globalisation also makes the world economy more vulnerable to crises that can spread rapidly from one country to another.

5. Technological and scientific advances

The period since 1945 has also been marked by extraordinary technological and scientific progress. Perhaps the most visible field has been space exploration. In 1957, the Soviet Union launched Sputnik, the first artificial satellite to orbit the Earth. This event shocked the United States, which feared that the Soviets were winning the technological race. In response, the US created NASA and launched its own space programme. In 1961, the Soviet cosmonaut Yuri Gagarin became the first human being to travel into space. However, the greatest triumph came in 1969, when the American astronaut Neil Armstrong became the first person to walk on the Moon. The Apollo 11 mission was watched by millions of people around the world on television and represented a great victory for the United States. Since then, space exploration has continued with the space shuttle, the International Space Station, the Hubble telescope and the exploration of Mars with robots such as Curiosity and Perseverance.

Another field of great progress has been medicine. After the war, the discovery of antibiotics, such as penicillin, saved millions of lives that would have been lost to infections. Vaccines were developed against polio, measles, mumps, rubella and many other diseases. The World Health Organisation led a successful campaign to eradicate smallpox, which was declared eradicated in 1980. Organ transplants, such as the first successful kidney transplant in 1954 and the first heart transplant in 1967 by Dr Christiaan Barnard, opened up new possibilities for treating previously fatal diseases. In recent decades, advances in genetics, such as the mapping of the human genome in 2003, have opened the door to new therapies and personalised medicine.

The development of computers and the internet has also changed the world profoundly. The first electronic computers, such as the ENIAC (1945) , were huge machines that occupied entire rooms and were used mainly for military or scientific calculations. In the 1970s and 1980s, the first personal computers appeared, such as the Apple II and the IBM PC, which brought computing power to homes and offices. The invention of the World Wide Web in 1989 by Tim Berners-Lee turned the internet into a global network of information accessible to anyone with a computer. Today, billions of people use the internet to communicate, work, study, shop, be entertained and access information. The digital revolution has changed the way we live, work and relate to each other, and it continues to evolve with the emergence of social media, artificial intelligence and big data.

Finally, the development of nuclear energy has been one of the most controversial advances. On the one hand, nuclear power plants produce large amounts of electricity without emitting greenhouse gases. On the other hand, nuclear accidents such as Chernobyl (1986) and Fukushima (2011) have shown the catastrophic consequences of a failure in a nuclear power plant. In addition, the problem of nuclear waste, which remains dangerous for thousands of years, has not yet been solved. The same nuclear technology that can provide clean energy can also be used to build nuclear weapons, which continue to pose a threat to world peace.

6. Social and cultural transformations

Society and culture also changed dramatically after 1945. One of the most important changes was the transformation of the role of women. During the war, many women had worked in factories and offices while the men were fighting. After the war, many women wanted to continue working and to have greater control over their own lives. The feminist movement gained strength, demanding equal pay, access to education and employment, and the right to control their own bodies. The invention of the contraceptive pill in the 1960s gave women unprecedented control over their fertility and allowed them to delay marriage and motherhood in order to pursue careers. In many countries, laws were passed giving women the right to vote, to own property, to obtain a divorce and to have access to abortion. Although much remains to be done, the position of women in society has improved dramatically since 1945.

Another great social movement was the civil rights movement in the United States. African Americans had suffered centuries of slavery and segregation. In the 1950s and 1960s, leaders such as Martin Luther King Jr. organised peaceful protests, boycotts and marches to demand an end to segregation and discrimination. The movement achieved important victories, such as the Civil Rights Act of 1964 and the Voting Rights Act of 1965, which outlawed racial discrimination. King was assassinated in 1968, but his legacy lives on. The civil rights movement inspired other movements, such as the gay rights movement and the disability rights movement.

Youth culture also emerged as a powerful force after the war. In the 1950s, rock and roll music, with artists such as Elvis Presley, rebelled against the conservative values of the older generation. In the 1960s, the counterculture movement rejected materialism, the Vietnam War and traditional authority. Young people experimented with new lifestyles, new music (The Beatles, The Rolling Stones, Jimi Hendrix) and new ideas about sex, drugs and spirituality. The Woodstock festival of 1969 became the symbol of this generation. Since then, youth culture has continued to evolve with the emergence of punk, hip hop, electronic music and the culture of social media.

Education also expanded dramatically after 1945. In many countries, free and compulsory education was extended to more years, and access to university increased significantly. This created a more educated population and facilitated social mobility. Finally, religion lost influence in many Western societies, a process known as secularisation. Fewer people attended church regularly, and moral values became more diverse and individualistic. At the same time, immigration from former colonies and other parts of the world transformed Western societies into more multicultural and diverse places, which brought both enrichment and social tensions.

7. The world after 1991: New challenges and new powers

With the end of the Cold War in 1991, the world entered a new phase. The United States remained as the only superpower, a position known as the "unipolar moment" . During the 1990s, the US promoted the expansion of democracy and the free market, a vision that the political scientist Francis Fukuyama called "the end of history" , suggesting that liberal democracy had triumphed definitively. However, this optimism was shattered by the terrorist attacks of September 11, 2001, when Al Qaeda hijacked four commercial aeroplanes and crashed two of them into the Twin Towers of the World Trade Center in New York. The United States launched a "war on terror" that included invasions of Afghanistan (2001) and Iraq (2003) , wars that have been long, costly and controversial.

At the same time, new powers have emerged. China has experienced spectacular economic growth since the 1980s and is now the second largest economy in the world. India, Brazil and other emerging countries have also grown rapidly. The world has become more multipolar, with several centres of economic and political power. The European Union has expanded to include many countries of Eastern Europe and has deepened its integration with the euro and the Schengen Area. However, the EU has also faced serious crises, such as the eurozone crisis (2010-2015) , the migration crisis (2015-2016) and the exit of the United Kingdom, known as Brexit (2020) .

Climate change has emerged as one of the greatest challenges of the twenty-first century. Scientists have shown that human activity, especially the burning of fossil fuels, is causing an increase in global temperatures, with potentially catastrophic consequences: rising sea levels, more frequent and intense extreme weather events, loss of biodiversity and threats to food and water security. International agreements, such as the Kyoto Protocol (1997) and the Paris Agreement (2015) , have attempted to coordinate a global response, but progress has been slow and insufficient.

Another major challenge is global inequality. Although globalisation has lifted millions of people out of poverty, especially in China and India, the gap between rich and poor within many countries has widened. The financial crisis of 2008 and the COVID-19 pandemic of 2020-2021 have exacerbated these inequalities and raised questions about the sustainability of the current economic model. Finally, the digital revolution has brought new challenges, such as the loss of privacy, the spread of disinformation, cyberattacks and the impact of automation on employment. In conclusion, the world has changed profoundly since 1945. The Cold War divided the world into two opposing blocs, decolonisation ended the old European empires, the economy experienced a golden age followed by crisis and globalisation, technology advanced at an unprecedented pace, and society and culture were transformed. The challenges of the present are different from those of the past, but the history of the period since 1945 teaches us that change is constant and that human beings have a remarkable capacity to adapt and to create new solutions to new problems.