The Korean Demilitarized Zone (DMZ) stands as a compelling destination for heritage tourism due to its rich historical and sociocultural significance. This study employs the psychological continuum model to explore allegiance development across four dimensions—awareness, attraction, attachment, and allegiance—within the context of DMZ tourism. The investigation delves into how DMZ tourists’ sociocultural motivation shapes their destination engagement, subsequently influencing emotional attachment and ultimately impacting revisit intention. Through a survey of DMZ visitors and the application of structural equation modeling, this study explores the dynamics of DMZ tourists’ allegiance. The findings reveal a positive relationship between sociocultural motivation and destination engagement, emotional attachment, and revisit intention. Destination engagement positively affects emotional attachment, albeit indirectly influencing revisit intention. Emotional attachment positively influences revisit intention. Furthermore, this study identifies notable moderating effects of DMZ tourists’ residency. Specifically, sociocultural motivation more strongly influences revisit intention, and destination engagement has a stronger impact on emotional attachment in international tourists compared to domestic tourists.