Which of the following best represents a direct outcome of nationalism in the context of World War I?

Nationalism, the strong identification with and pride in one's nation, significantly influenced societal attitudes and behaviors during World War I. A direct outcome of this sentiment was a surge in military enlistment. As nations rallied their citizens under the banner of patriotism, many individuals felt a strong obligation to serve their country. This was particularly evident in the fervor around recruitment drives, where patriotic appeals encouraged young men to join the military in defense of their nation.

Many perceived military service as a duty and a show of loyalty, driven by the belief that their nation was superior or morally justified in its actions. This environment created a sense of urgency and camaraderie, leading to a notable increase in enlistment numbers as the war unfolded.

In contrast, although increased diplomacy and global trade expansion occurred to some extent in the broader context of international relations, they do not directly stem from nationalist fervor but rather from the complexities of world politics and economic factors. Isolationist sentiments arose after the war, reflecting a reaction against the involvement in foreign conflicts rather than a direct outcome of nationalism during the war itself.