The Indonesia  - Australia relationship is a distinctive neighborly relationship; the 2013-2025 period features cycles of strain and consolidation against the backdrop of 76 years of diplomatic ties. This study aims, from a Realist perspective, to explain why the relationship recovered after the 2015 rupture and continued to deepen through 2025, while filling the explanatory gap for 2015-2021. The study employed qualitative methods, including documentary analysis, the historical method, and process tracing, together with descriptive indicators of trade, FDI, and ODA. The study argues that the 2013-2025 recovery and upgrading of Indonesia-Australia relations were driven primarily by calculations of power and material interests and threat perceptions, institutionalized through milestones such as the 2018 Comprehensive Strategic Partnership and the 2019 IA-CEPA. This study concludes that the convergence of core strategic interests is the anchor of the bilateral relationship; for durability, both sides should proactively institutionalize cooperation, maintain transparent dialogue and coordinate in multilateral fora, and contribute to a stable, rules-based regional order.