Prior to the armistice, several Allied Streifkorps conducted operations in the rear of the French army ranging from raids and surprise attacks to severing imperial communications. Pressing deep into Thuringia, a portion of Lützow’s Streifkorps outdistanced Allied communications and for a while remained uninformed of the armistice. After learning of the cessation of hostilities, the small unit attempted to reach Allied lines. Yet on 17 June a superior French and Württemberger force attacked and routed the Prussians at Kitzen near Leipzig, purportedly on Napoleon’s order. Those who surrendered spent the next nine months aboard France’s notorious prison hulks. Emphatic Allied protests fell on deaf ears. Blücher, Gneisenau, Bülow, and several other high-ranking Prussian officers loudly claimed that this French treachery rendered the armistice void. They particularly urged the termination of Article Five, which stipulated that the besieged imperial garrisons at Danzig, Zamosc (Zamość), Modlin (Nowy Dwór Mazowiecki), Stettin, and Küstrin (Kostrzyn) each receive fresh supplies every five days. Frederick William and Alexander agreed, forcing the imperials to tighten their belts. The early surrender of these fortresses can be attributed to the threat of starvation caused by this measure.

During June and July, the Coalition’s uncertain future forced the Prussians in Silesia to plan for the worst. Should the Sixth Coalition collapse and the Russians withdraw to Poland, Gneisenau planned to position the Prussian army in the mountains of Upper Silesia. Supported by the fortresses of Neiße (Nysa), Glatz, and Silberberg (Srebrna Gόrna), he envisioned the army fighting to the last man. Frederick William named him military governor of Silesia, tasking the staff officer with the defense of the province and the mobilization of the Silesian Landwehr. “Return to me when the feud resumes,” Blücher begged Gneisenau. “In every regard it is necessary that we are together.”