How does war affect states’ tolerance toward foreign culture? It is well documented by historians that democratic countries, despite their heralded values of liberty and diversity, acquiesce and even promote the practice of cultural intolerance in wartime. The available evidence, however, remains either anecdotal or limited to a specific context, and the extent to which war-induced cultural intolerance persists has so far rarely been examined. In order to investigate the short- and long-term effects of war on the degree of foreign cultural acceptance, this article focuses on patterns of classical music performances before, during, and after the two World Wars, based on a novel dataset assembled from concert program notes of ten renowned symphony orchestras from five countries (Austria, Germany, Japan, the United Kingdom, and the United States) between 1900 and 1960, covering 29,135 concerts and 125,530 pieces. Quantitative analysis suggests that the rate of performing pieces originating from belligerent countries in wartime declines markedly for music written in relatively modern times and that the defeat in wars led to a swift recovery of the exclusionary tendency against former enemy music. These findings demonstrate that states’ security concerns and relative power, rather than political regime types, dictate international transaction patterns, including cultural flows across sovereign state borders.