The 20th century was marked by several significant wars that shaped the world. The two World Wars, World War I and World War II, involved many countries and resulted in millions of casualties. These conflicts were driven by complex political alliances, nationalism, and economic struggles, leading to widespread destruction and changes in global power dynamics. In addition to the World Wars, other notable conflicts included the Korean War and the Vietnam War, which were influenced by the Cold War tensions between the United States and the Soviet Union. These wars highlighted the struggle between communism and democracy, leaving lasting impacts on the countries involved and the world at large.