This study investigated the complex intersection of cultural identity, intercultural sensitivity, and pronunciation adaptability among undergraduate English majors at a Vietnamese public university. Utilizing an explanatory sequential mixed-methods design, the research examined how learners navigate the psychological tension between preserving their regional accent and ensuring mutual intelligibility in global contexts. Quantitative survey findings revealed that intercultural sensitivity strongly and positively predicts a learner's willingness to pragmatically modify speech features. Qualitative interview data further demonstrated that this balance is maintained through a strategic phonological hierarchy; learners actively prioritize features aligned with the Lingua Franca Core to prevent communication breakdown while comfortably retaining localized accent markers to preserve their cultural roots. Ultimately, the study suggests shifting from rigid native-speaker norms toward an intercultural language framework that rewards pragmatic flexibility, adaptive communication strategies, and co-constructed mutual understanding.