This article introduces into scientific circulation an address by Emperor Alexander I to the commanders of the Russian army. It emphasizes the inadmissibility of hostile sentiments toward allies. This document testifies to serious political and ideological contradictions that existed between the Austrian and Russian officers during the War of the Third Anti-French Coalition (1805). Through internal and external criticism of the source, it is possible to establish the date and place of its creation. Based on this, the author concludes that this address was of great importance for the coalition war. Russo-Austrian contradictions, rooted in historical, political, and cultural factors, proved so significant that they required a personal appeal from the tsar to the officer corps. At the same time, the document under consideration allows for a more nuanced understanding of the idea that the Russian nobility could not have initiated the war against Napoleon.