What document defines the term "extremists" within the army?

The document that defines the term "extremists" within the Army is DA PAM 600-15. This pamphlet specifically focuses on the Army's stance against extremism, providing policy guidance on the identification and management of extremist activities within the ranks. It outlines the expectations for behavior and the consequences of engaging in extremist ideologies or actions, thus serving a critical role in ensuring a respectful and inclusive environment within the Army.

In contrast, the other documents mentioned do not address the definition or policy regarding extremism. FM 3-24 is primarily concerned with counterinsurgency operations and strategies, AR 670-1 governs the wear and appearance of Army uniforms, and DA Form 4856 is a developmental counseling form used to provide feedback to soldiers. Each of these serves a different purpose related to Army operations and personnel management, but none specifically define the concept of extremism as outlined in DA PAM 600-15.