<p>Disorganized attachment has been associated with caregiving adversity and increased vulnerability to later emotional and relational difficulties, yet the mechanisms underlying the breakdown of organized attachment behavior remain incompletely specified. This paper proposes a brainstem-informed conceptual framework that understands disorganized attachment as the expression of a motivational conflict between attachment-related approach and defensive avoidance under conditions of relational threat. Integrating insights from attachment theory, evolutionary perspectives, and affective neuroscience, the framework distinguishes levels of analysis and clarifies the relationship between attachment classifications, system-level disruption, and observable disorganized behaviors. Focusing on early-integrating sensorimotor systems, the paper identifies midbrain mechanisms involved in orienting and action selection as a plausible locus for the behavioral expression of attachment–defense conflict. This account explains contradictory, fragmented, or poorly sequenced attachment behaviors as reflecting variability and instability in early orienting and action selection processes, complementing models that emphasize higher-order regulatory systems without reducing attachment phenomena to neural mechanisms alone. Under conditions of ambiguous or inconsistent relational threat, increased variability and instability in orienting and action selection processes should be observed, whereas under more explicit threat responses should become more stable and defense-dominated; disorganized behaviors are further expected to involve dynamic fluctuations in gaze orienting, motor sequencing, and autonomic regulation. By adopting a context-sensitive and developmental perspective, the framework accommodates heterogeneity in disorganized attachment and highlights how vulnerability may be modulated across relational contexts, while outlining directions for future empirical research.</p>