Any US-Iran bilateral arrangement finalized before December 31, 2026 will be structured as a short-duration executive framework — interim understanding, temporary sanctions relief, or informal compliance arrangement — with a formal compliance or verification horizon of 4 years or fewer, failing to extend enforcement commitments beyond the current US presidential term (ending January 2029). If no arrangement is reached by December 31, 2026, the prediction is confirmed by default: the bilateral duration trap will have prevented agreement entirely.

DURATION (1236): Duration mismatch between institutional time-horizons is a seigniorage mechanism — the actor who can exit the short-duration contract captures the premium while the long-duration risk falls to whoever cannot exit. In the US-Iran case, the executive agreement is the short-duration contract: the administration captures the political premium (diplomatic achievement, market confidence) within the electoral cycle, while the structural risk (nuclear breakout, regional proxy architecture, Hormuz passage security) persists beyond the agreement’s enforcement horizon. The ‘residual’ — the risk that outlasts the agreement — falls to successor administrations and to the populations in the Gulf region who cannot exit the structural exposure. → BILATERAL (160, 1257): The bilateral form creates a legibility trap that amplifies the duration mismatch. The bilateral presents a structurally multilateral problem (Hormuz involves Gulf states, global energy markets, EU, China, Russia, India) as a two-party negotiation, making it appear nationally legible and subject to zero-sum evaluation. Each side’s electorate reads the bilateral through the national grammar: concessions are visible bilateral losses (short-duration, domestically processable), while structural gains (stability, de-escalation, economic integration) diffuse beyond the bilateral frame and cannot be captured as political credit within either country’s electoral cycle. → INTERSECTION: The bilateral form prevents long-duration agreements because the form renders short-duration costs legible and long-duration benefits illegible. The concession is immediately processable in the national grammar (‘we gave them sanctions relief’); the structural benefit operates on a timeline (decades of enrichment limitation, generational Hormuz stability) that exceeds the bilateral form’s evaluative horizon. No domestic constituency can form around benefits that take 10-15 years to materialize, while the constituency opposing concessions forms immediately. The duration mismatch is therefore not a temporal accident but a structural product of the bilateral form’s legibility architecture — the form produces the mismatch by making short-duration information legible and long-duration information grammatically inexpressible. → MEANS-TEST ANALOGY (255): The bilateral agreement installs the same epistemic segregation the means-test installs: compliance is ‘read’ at verification snapshots (the assessment appointment), while the structural trajectory between snapshots (the durational experience of risk accumulation) remains unprocessed. The agreement reads the counterparty the way the assessor reads the claimant — at the tempum of the verification moment, not across the duration of the structural problem.