This article offers a comparative analysis of how the First World War affected emerging Estonian, Latvian and Lithuanian nationalisms. There has been a clear tendency to treat the three states declared by these national movements in 1918 as a single ‘Baltic’ grouping created as a result of common factors and processes. Yet, such a characterisation downplays differences which arise due to the position of the region at the very frontline of the war in the East, which brought a variety of jurisdictions and political contexts. A further tendency has been to retrospectively portray the nationstate framework ultimately created in all three cases as the realisation of the long-cherished goal of the pre-1918 national movements. Such an understanding of national self-determination, however, only emerged much later, and federalist thinking continued to shape both external and internal conceptions of sovereignty during and immediately after the war. How statehood was conceived, moreover, had a lot to do with which side of the line a region was located during the conflict, with key points of difference being discernible between the Estonian and Lithuanian cases in particular.