Abstract This paper addresses the problem of identity persistence under transformation: what must be true for the same/not-same relation across recurrence to be meaningful, non-arbitrary, and non-trivial. Starting from these minimal conditions, a forcing chain is derived. The Tier-1 axiom set governing identity persistence is shown to be necessary, not assumed. Identity-relevant recurrence collapses to a single degree of freedom, forming a one-dimensional trunk. The domain of this trunk is forced to satisfy three structural conditions: bounded re-comparability, coherent single-domain identity support, and non-terminal recurrence. Within this regime, there exists a canonical topological realization in which the recurrence domain is compact, connected, and boundaryless. In the one-dimensional case, this realization corresponds to S1. This induces an SO(2) symmetry class with an O(2) chiral extension, which fixes the invariant vocabulary to harmonic components r_k and orientation-sensitive components chi_k. Under compositional closure, structural regularity, and gauge invariance, identity governance is forced to be scalar, additive, and linear over this invariant basis. The admissible class of governance functionals collapses to positive linear combinations, yielding a unique functional of the form: PAS_h = sum over k of (w_k * r_k) This functional is unique up to affine gauge transformation. Identity persistence is therefore equivalent to bounded scalar drift under PAS_h. At the substrate level, any system sufficient for identity persistence is minimal and irreducible, implementing exactly four structural roles: state support, recurrence progression, compositional aggregation, and recurrence-domain support. All admissible substrates collapse to a single structural form up to forcing-equivalence. At the meta level, the space of Tier-1 structural statements is exhausted. No additional independent axiom or constraint remains within the identity persistence problem once the forcing chain is complete. The result is a structural forcing theorem establishing closure of identity persistence within a defined regime. It does not claim ontological instantiation or unrestricted completeness across all conceivable formal systems. It does establish invariance across all admissible reformulations and across all admissible rival frameworks that preserve the same identity-persistence problem. The remaining open question is whether any genuinely non-equivalent framework preserving that same problem exists.