World Wars I and II had a profound and long-lasting impact on the global economy. In 1914, World War I (WWI) began and ended in 1918, leaving behind huge losses in terms of resources and population. Many countries experienced severe infrastructure damage, forcing them to divert resources from production to reconstruction. For example, the European economy was in decline, with countries such as France and Germany facing huge war debts. After WWI, a slow economic revival could not overcome the problems of high inflation and mass unemployment, creating political instability that contributed to the rise of extremist ideologies. The Great Depression of the late 1920s, triggered by the stock market crisis of 1929, further worsened the situation. Many countries implement protectionist policies, such as high tariffs, which slow international trade and create a cycle of global economic decline. World War II (WWII), which lasted from 1939 to 1945, brought major changes in global economic dynamics. In this period, countries engaged in total war, diverting all their resources to military industry. The US, as a major power, experienced a surge in industrial production and created millions of new jobs. The US’s role as a provider of goods and services to its allies strengthened its position in the post-war global economy. After WWII ended, the Marshall Plan launched by the US helped restore the European economy by providing significant financial assistance. This created greater European economic integration and facilitated the creation of the European Economic Community (EEC) in 1957. In Asia, Japan emerged from the ruins of war with an aggressive industrialization strategy, making it one of the world’s largest economies by the 1960s. The emergence of international institutions, such as the International Monetary Fund (IMF) and the World Bank, in the post-war era also contributed to global economic stability. They serve to help countries in economic crisis and support sustainable development. Additionally, the shift of economic power from Europe to the US and Japan marked a new phase in the global economy. The war also affected trade patterns. The more liberal trade policies of many post-WWII countries allowed for deeper market integration. The World Trade Organization (WTO) which was formed in 1995 reflects the commitment of countries to expand international trade, creating a more complex global economic network. On the other hand, the social impacts that occur as a result of war are also long-lasting. Demographic changes, such as massive population movements and gender changes in the Labor Force, affect the structure of the labor market. Women’s entry into the job market during the war set new norms and sparked the rise of the women’s movement. Apart from that, the environmental impact of war and reconstruction cannot be ignored. Rapid recovery often leads to unsustainable exploitation of resources, giving rise to long-lasting environmental problems. Overall, although both World Wars brought destruction, they also created opportunities for economic revitalization, innovation, and global integration that have shaped today’s modern economies.