Türkiye, the EU, and the post-war order in the South Caucasus: the limits of converting wartime access into durable regional influence

How do middle powers transform short-lived, military-enabled opportunities into enduring regional influence without seizing territory? This article examines Türkiye's post-2020 strategy in the South Caucasus amid European Union and United States rule-setting, developing an alliance-platform framework with two potentially non-linear conversion pathways: embedded security management and connectivity leverage. A plausibility probe of the Turkish case (September 2020–September 2025) draws on twenty-nine coded documents, including Turkish, Azerbaijani, and Armenian official sources, and six expert interviews. The analysis distinguishes temporal compatibility from documentary evidence of transmission and assesses the outcome separately through agenda-setting, preference-shaping, exclusion costs, institutional access, and recognition. The alliance platform was codified; the monitoring role ended in 2024; and the post-2020 connectivity pathway produced no documented Turkish rule-setting authority. The case therefore disconfirms a strict transmission claim between the two pathways, and the outcome indicators do not independently sustain an aggregate finding of durable influence. That negative result is the contribution: on a most-likely case, the inference from persistent instruments to durable influence fails an independence test. The article supplies the standard that test requires, and a bounded account in which a codified alliance may enable, but does not demonstrate, separate and reversible routes to regional influence.