How did World War I increase attention to military espionage and sabotage?

World War I served as a critical turning point that heightened global awareness regarding the necessity of robust security and protection systems to defend against military espionage, sabotage, and subversion.1

Prior to the conflict, many nations lacked coordinated intelligence or internal security frameworks. For example, in the United States, the absence of a central organization led to significant confusion, with more than 20 different agencies attempting to manage security investigations during the war. This fragmented approach proved inadequate for addressing the sophisticated threats posed by foreign powers.23

The experience of the war demonstrated that such programs were essential components of a nation's national-security infrastructure. Consequently, the lessons learned during this period—and the subsequent international tensions—led to the retention and professionalization of these security apparatuses. This shift laid the groundwork for the modern, integrated intelligence and counterintelligence systems that emerged in the following decades, moving away from the disorganized, often vigilante-style efforts that characterized the early war years.12