This November 11th marks the centenary of the ceasefire that ended World War I, and which gave that date the name Armistice Day, called Veterans Day in the United States. On the 11th hour of the 11th day of the 11th month of 1918, Germany, which was the dominant partner among the Central Powers and the last still waging war, signed an agreement with the Allied powers to stop fighting.

The November 1918 armistice ended combat in a conflict whose death toll is unimaginable. Between eight and ten million soldiers died in the war, more than 21 million others were wounded, and nearly seven million civilians perished, many from starvation and disease. These figures do not include the uncountable millions who died during the Spanish influenza pandemic that began in the war’s last year, nor the many casualties of the battles that took place after the armistice was signed. The Great War hit some countries particularly hard. One out of every 23 individuals alive in France in July 1914 was dead by the end of 1918 because of the war. Serbia fared even worse, with one out of every six people in that country dying in combat or from war-related causes. For the sake of comparison, roughly one of every 133,000 people in the U.S. has died fighting in Afghanistan, a conflict now stretching into its 17th year.

The Great War, later known as the First World War, was a truly worldwide conflict with a sprawling global reach. Combat zones emerged across continental Europe, in southwest Asia and the Middle East, in northern China, in both Atlantic and Pacific oceans, and in eastern, southern, and western Africa. The war also affected regions and peoples located well beyond its actual battlefronts. France recruited hundreds of thousands of troops and workers from its colonial territories, including Algeria, French West Africa, and French Indochina. Hundreds of thousands of Indians and tens of thousands of Africans saw service in defense of Britain and its empire, as did many thousands of Australians, Kiwis, Canadians and British subjects from the Caribbean. In addition, tens of thousands of Chinese supported the Entente’s war efforts as laborers behind the Western Front.

Another distant land involved was the United States, which declared war on Germany in April 1917, and whose troops started showing up in significant numbers in Europe in January 1918. In all, more than 4,000,000 Americans of diverse backgrounds served in the military: 18 percent of U.S. Army soldiers were foreign-born, and African-Americans made up 13 percent of recruits even though they constituted only 10 percent of the country’s population. More than 53,000 U.S. soldiers perished of battle wounds and another 63,000 of disease or other causes. Hundreds of students, alumni, faculty, and staff at my home institution, Berry College, either enlisted, served behind the lines as nurses, or materially supported the war from the home front. Eleven of the “Berry Boys” who enlisted made the ultimate sacrifice.

Although the 1918 armistice was meant to bring about an end to hostilities, war continued for years in some places. Street fighting recurred for months in cities in Germany. For Russia, where total war had led to defeat and revolution, the Great War was followed by an armed conflict with newly re-emergent Poland that lasted into 1921 and a civil war at home that did not end until 1922. The political and social instability that World War I unleashed led to ongoing combat in Ireland and Turkey, as well as in the colonial world where Europe’s imperial powers fought rebellions for years, often using surplus equipment and leftover munitions from 1914-18.

The attempts at peacemaking that followed the November 1918 armistice failed, and famously so. In the U.S., disillusionment with the war’s results led to a “lost generation” of younger Americans, epitomized by writers like Ernest Hemingway, John Dos Passos, and F. Scott Fitzgerald, all of whom left the country for a time. U.S. leaders became more isolationist and failed to promote international collaboration, signaled early on by the Senate’s 1920 decision not to ratify the Treaty of Versailles, a peace agreement U.S. president Woodrow Wilson had played a lead role in drafting. Rather than encourage international cooperation and collective security, U.S. leaders engaged abroad only insofar as it would put America first, for instance by negotiating the 1924 Dawes Plan to ensure repayment on wartime loans. The country also closed itself off from the world by severely restricting immigration. Looking to advance narrow U.S. interests, the government raised tariffs, which sapped international goodwill, hurt global trade, worsened the post-war economic downturn, and encumbered those nations trying to repay war debts. As authoritarian leaders came to power in countries across Europe and elsewhere after the war, the U.S. maintained its inward-looking, America-first attitude, which sapped the country’s ability to do anything about international crises.

It took a second and even more destructive world war for U.S. leaders to learn the many advantages of overseas engagement and the benefits of deliberate, constructive support of international efforts at cooperation. Many multinational organizations that emerged after the Second World War, including the North Atlantic Treaty Organization and, eventually, the European Union, were critical to safeguarding U.S. security and prosperity, and they have contributed to more than seven decades of relative peace. Now a century removed from the armistice that ended the Great War, let us hope it is not too late for U.S. leaders — and the voters whose responsibility it is to choose them — to learn from past experience.

Matthew G. Stanard, Ph.D., is a professor of history at Berry College.