Rethinking flood defence planning under climate uncertainty: a no-regret perspective for Vietnam

Purpose This perspective paper examines how no-regret thinking (NrT) can support climate-adaptive flood defence planning (FDP) in Vietnam under increasing climate uncertainty. It argues that conventional flood defence approaches remain constrained by short-term planning priorities and proposes a broader resilience-oriented perspective to support long-term infrastructure decision-making. Design/methodology/approach The paper adopts a conceptual and policy perspective informed by climate adaptation, resilience and flood risk management literature. Drawing on the Vietnamese context, it critically discusses the limitations of conventional FDP and synthesises existing adaptation concepts to develop a no-regret perspective for climate-adaptive FDP. Findings The paper argues that no-regret approaches (NrAs) provide an overarching decision-making philosophy that complements existing adaptation approaches by promoting long-term societal protection, preventative adaptation, integrated planning and intergenerational responsibility. Rather than replacing existing strategies, NrAs offer a common framework for evaluating, prioritising and integrating flood defence investments under conditions of deep climate uncertainty. Research limitations/implications This paper is conceptual in nature and does not include empirical testing or quantitative modelling. Future research may further operationalise NrAs through adaptive planning frameworks, governance analysis and resilience-oriented decision support systems. Practical implications The paper highlights the importance of integrating long-term resilience considerations into FDP, governance, and infrastructure investment decisions under uncertain future climate conditions. Social implications The paper emphasises the societal importance of flood defence infrastructure in protecting communities, reducing long-term vulnerability, and supporting intergenerational resilience under climate uncertainty. Originality/value This paper extends the discussion of NrT into the context of FDP in Vietnam. By positioning NrAs as an overarching planning philosophy rather than a standalone adaptation measure, the paper provides a novel conceptual perspective for supporting more robust, flexible and climate-adaptive infrastructure decision-making in Vietnam and other climate-vulnerable developing countries.