The Great War was the United States’ first serious encounter with European conflict and global diplomacy.

From The Long Shadow by David Reynolds.  Page XXI

The United States was even more distant from the Great War, both geographically and emotionally, and its growing disillusion about what the conflict had achieved paralleled that of the United Kingdom. The crucial difference, however, was the body count. The UK death toll was 723,000, the US figure 116,000—more than half of them actually soldiers who fell victim to the influenza pandemic of 1918. It was the imbalance between, on the one hand, the magnitude of British losses and, on the other, the remoteness of the issues apparently at stake that created the sense of anguish in Britain about the Great War. For Americans, who suffered much less and more briefly, the war of 1917–18 was then overshadowed by the titanic struggles of 1941–45 and the Cold War. Yet the Great War was the United States’ first serious encounter with European conflict and global diplomacy. It would prove a benchmark all through the twentieth century for American leaders as they wrestled with the political burdens and moral dilemmas of being a world power.