Relativistic jets from Active Galactic Nuclei (AGN) are among the most energetic and coherent structures in the universe, yet several of their defining properties remain poorly understood. While existing models successfully identify rotational energy extraction from spinning black holes and magnetized accretion disks as the power source, they do not fully explain the extreme collimation, long-range coherence, bipolar symmetry, or abrupt onset and quenching of jets. This paper proposes a global coherence perspective in which the black hole–disk–magnetosphere system is treated as a single rotating dynamical structure subject to large-scale organizational constraints. Within this view, jets arise as preferred channels that preserve global coherence when internal rotational stress exceeds a critical threshold. Abrupt AGN state transitions are interpreted as crossings of such coherence thresholds rather than as gradual responses to changing accretion conditions. This framework does not replace magnetohydrodynamic descriptions but clarifies the conditions under which they succeed. The paper derives several observationally testable predictions concerning jet collimation, stability, handedness, and state hysteresis that distinguish global coherence constraints from purely local plasma dynamics.