The Infrastructure Interdependence Report™ (IIR™) presents a consolidated four-quarter record of observed conditions across interconnected infrastructure environments from Q3 2025 through Q2 2026. Published by the Institutional Continuity Observatory™, the report records developments visible across infrastructure ecosystems and examines relationships between infrastructures rather than infrastructure assets themselves. Observations are derived from published institutional evidence, regulatory publications, multilateral reports, parliamentary records, industry governance documents, and public policy materials. The report documents developments across infrastructure interfaces and explores how infrastructure interdependencies influence continuity conditions across contemporary environments. Particular attention is given to developments that become visible before broader consequences emerge. The report is not an assessment, ranking, rating, evaluation, forecast, or warning. It is an observatory record intended to support institutional reflection and public understanding of infrastructure conditions observable from the published record. Published by the Institute for Decision Infrastructure™.