The legacy of Petr Berngardovich Struve as a historian has received considerably less scholarly attention than his contributions to social thought, economic theory, and political journalism. Struve produced relatively few works devoted specifically to Russian history. In a number of shorter publications written before the Revolution, however, he formulated the idea of a Great Russia and situated it within the broader context of Russian historical development. Several of his articles were devoted to Russian historians, primarily in connection with his interest in the formation of Russian national consciousness. Struve's principal historical work, The Social and Economic History of Russia from the Earliest Times to the Present, in Connection with the Development of Russian Culture and the Growth of Russian Statehood, remained unfinished, yet may nevertheless be regarded as a major contribution to the traditions not only of Russian historiography but also of Russian historiosophy. The work reveals the close relationship between Struve's conception of history and his understanding of nationalism and patriotism and, in effect, articulates a distinctive "philosophy of patriotism". In Struve's interpretation, patriotism and nationalism are essentially identical concepts, representing two manifestations of national sentiment. The article draws particular attention to the contradictions inherent in Struve's concept of "true nationalism", whose only genuine form, in his view, was liberalism. During his years in emigration, the complexity and internal tensions of his understanding of these concepts became especially apparent on the eve of and during the Second World War, when the Russian émigré community was compelled to define its attitude toward Bolshevik rule against the background of the threat to Russia's independence. The divergence between Struve's theoretical convictions and his practical political position – most notably in relation to Russia and Germany — became evident in his publications of the 1930s. Although the intensity of the controversy within the Russian émigré milieu over this issue has already been examined in the scholarly literature, the documents discussed in the present article, particularly the testimony of Struve's close friend E.D. Kuskova, add important detail to the picture of the dramatic inner "split" between Struve the scholar and Struve the political thinker.