Purpose This exploratory qualitative study investigates why sustainable tourism behavior frequently fails to materialize despite strong environmental intentions. Drawing on social practice theory and behavioral affordance frameworks, it explores how domestic and international tourists differ in the mechanisms through which intentions translate – or fail to translate – into action at the same destination, and how destination infrastructure enables or constrains that process. Design/methodology/approach A qualitative interpretive design was employed, comprising 28 in-depth semi-structured interviews with domestic Vietnamese tourists (n = 13) and international tourists from 11 countries (n = 15) in Ho Chi Minh City. Participants were recruited through purposive and snowball sampling. Reflexive thematic analysis following an abductive logic was used to develop codes iteratively between data and theory, with trustworthiness established through member checking, negative case analysis and theoretical saturation. Findings Two structurally distinct behavioral logics are identified. Many domestic tourists enact sustainable behavior through embedded socialization – habitual routines, regional identity and situationally triggered social empathy – without explicit environmental intention. Some international tourists exhibit strong sustainable motivation but are constrained by the absence of the physical, regulatory and informational infrastructure through which their practices were formed. The persistent failure to act often reflects infrastructural misalignment rather than motivational deficit, though both mechanisms may coexist. Practical implications Destination managers should adopt a dual-track strategy: constitutive infrastructure investment (refill stations, mandatory charges, multilingual behavior-specific signage) for international tourists, and social-visibility design (community-framed communication, staff-delivered empathy cues, itinerary design enabling local contact) for domestic tourists. Choice architecture – making sustainable options the default – is identified as the most scalable intervention across both groups. Originality/value This study proposes embedded sustainability and infrastructural reliance as mechanism-level analytical constructs, reframes the attitude–behavior gap as a system–behavior misalignment and extends social practice theory by showing that sustainable practices are infrastructurally contingent – their reproduction depends on material and regulatory supports that may not travel across destinations.
Mai et al. (Wed,) studied this question.