Abstract International Relations has a developed literature on interstate trust, yet it largely treats trust either as a relationship-level disposition — ally or rival — or as a single aggregate measure of one state’s confidence in another. Both collapse a multi-dimensional construct into a scalar. This paper proposes that trust between two states is better understood as a vector: a set of distinct layers — security, trade, culture, finance, law enforcement, regulatory standards and others — held simultaneously, each occupying a different height on one continuous spectrum and governed by a different incentive structure. The height of any layer is set by what I term trust at risk: the expected unrecoverable loss to a party should the counterparty defect at that layer, operationalised as severity × irreversibility, and conceived as a deliberate transposition of value-at-risk into the diplomatic domain. The model’s central mechanism is negative trust convexity: the loss from a defection, and the time required to recover from it, scale non-linearly with the height at which the breach occurs, so that the highest-trust layers carry a payoff structure asymmetric to the trusting party’s detriment, directly analogous to negative convexity in fixed-income instruments. The framework yields an endogenous account of contemporary order recalibration, and because trust at risk is expressed as a priced, unrecoverable loss, it crosses cleanly into risk and capital-allocation applications. The paper builds on the author’s earlier work on Circles of Trust and on the dynamic weighting of international-system influence.