Modern World War refers to global conflicts involving many countries in the 20th and 21st centuries. The two main events considered to be World Wars are World War I (1914-1918) and World War II (1939-1945). These two wars changed the world’s political, economic, and social landscape dramatically, influencing international policy and relations between countries. World War I began with the assassination of Archduke Franz Ferdinand of Austria, sparking a series of alliances and rivalries in Europe. The consequences of this war included the collapse of the Austro-Hungarian Empire and the Ottoman Empire, as well as the emergence of new states such as Czechoslovakia and Yugoslavia. The years following the war were marked by the need for peace treaties, such as the Treaty of Versailles, which imposed heavy sanctions on Germany, fueling the conditions underlying the rise of extremist ideology. World War II began with German aggression in Europe and Japan in Asia. This war involved more than 100 million people from 30 countries, making it one of the most widespread conflicts in history. The impact of this conflict was severe, with an estimated 70-85 million lives lost, many of them as a result of genocide, such as the Holocaust. The post-war world map also experienced significant changes, with the emergence of the Soviet Union and the United States as the two dominant global powers, starting the Cold War era. Apart from that, Modern World War also includes various regional conflicts that have global potential, such as the Korean War (1950-1953) and the Vietnam War (1955-1975). Both are manifestations of tensions between the Western and Eastern blocs. In this context, the Cold War became a term that included tensions without open armed conflict between the United States and the Soviet Union, which also influenced the foreign policies of countries around the world. The advancement of military technology during the Modern World War was also extraordinary, with innovations such as airplanes, tanks, and nuclear weapons. Nuclear weapons, in particular, changed warfare tactics and upended humanity’s view of warfare. With the Strategic Arms Reduction Treaty, the world sought to avoid a potential nuclear catastrophe. Over time, modern conflict is shifting to new forms, including asymmetric warfare, terrorism, and cyber conflict, reflecting the need to adapt to changes in global technology and strategy. In this case, redefining the concepts of war and peace continues to be a challenge for countries in the world. Modern World Wars not only left scars on the land and souls of the countries involved, but also created the foundation for in-depth discussions about security, human rights, and humanity. Analysis of the social and economic impacts of this conflict is important for society’s understanding of the past, as well as its impact on the future of world peace. International relations, diplomatic engagement and conflict resolution are key in efforts to maintain global stability today.