Infrastructure Determinism examines how modern societies are shaped less by explicit policies or political intentions and more by the infrastructures that operationalize them. Drawing on systems theory, institutional analysis, and political economy, the essay argues that infrastructures—bureaucratic, digital, legal, economic, and physical—function as long‑duration structures that determine social outcomes. Once established, infrastructures outlive their creators, define who is legible to institutions, reproduce inequity automatically, and set the pace and direction of social change. The essay positions infrastructure determinism as a diagnostic lens for understanding why reforms often fail, why inequities persist despite policy commitments, and why meaningful change requires architectural reconstruction rather than rhetorical updates. This work is part of the SignalRupture (SR) framework, which analyzes how systems govern recognition, access, and possibility.