What major multilateral conflict involved the Central Powers during the early 20th century?

The major multilateral conflict that involved the Central Powers during the early 20th century is World War I. The Central Powers, primarily consisting of Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria, were pitted against the Allied Powers, which included countries like France, the United Kingdom, Russia, and later the United States. This global conflict lasted from 1914 to 1918 and is characterized by extensive trench warfare and significant geopolitical changes.

World War I marked a pivotal moment in history, reshaping national borders, leading to the fall of empires, and setting the stage for future conflicts, including World War II. The consequences of the war included political upheaval, economic turmoil, and social changes across nations involved.

In contrast, the other conflicts listed occurred later or involved different nations and circumstances. World War II, for example, although a significant multilateral conflict, did not involve the Central Powers, as that term is specifically associated with World War I. The Korean War and Vietnam War occurred in the mid-20th century and were primarily conflicts involving different geopolitical frameworks and factions. Therefore, World War I is the correct answer to the question concerning the early 20th century and the Central Powers.