Love is treated in this work as a universal relational operator rather than an emotion, preference, or moral category. The operator is defined by a single invariant: it expands another agent’s capacity to act while preserving the coherence of one’s own agency. This structural framing makes love a substrate‑neutral mechanism that applies to persons, collectives, and artificial systems. The paper identifies the minimal relational conditions under which the operator can exist—recognition, constraint modeling, non‑destructive intervention, and self‑coherence—and shows that its lowest actionable form is help, the smallest intervention that increases another agent’s agency. Building from this base, the analysis develops an operational ladder of relational expansion (help, support, care, commitment, love) and demonstrates that each rung is generated by repeating the same minimal move under increasing modeling and stability requirements. The paper also characterizes the predictable breakdown modes associated with each rung, revealing a structural symmetry between expansion and collapse. By grounding love in relational mechanics rather than sentiment, the work provides a unified account of how agency can be expanded across scales and substrates, offering a general framework for understanding relational action in human, social, and artificial systems.