Tukhachevsky, certain that all was going according to plan, was actually falling into Piłsudski's trap. There were only token Polish resistance in the path of the main Russian advance north and across the Vistula, on the right flank of the battle (from the perspective of the Soviet advance). At the same time, south of Warsaw, on the battle's left front, the vital link between the Northwestern and Southwestern Fronts was much more vulnerable, protected only by a small Soviet force, the Mozyr Group. Further, Semyon Budyonny, commanding the 1st Cavalry Army, a unit much feared by Piłsudski and other Polish commanders, disobeyed orders by the Soviet High Command, which at Tukhachevsky's insistence, ordered him to advance at Warsaw from the south. Budyonny resented this order, influenced by a grudge between commanding South-Western Front generals Alexander Ilyich Yegorov and Tukhachevsky. In addition, the political games of Joseph Stalin, at the time the chief political commissar of the South-Western Front, further contributed to Yegorov's and Budyonny's disobedience. Stalin, looking for personal glory, aimed to capture the besieged Lwów (Lviv), an important industrial center. Ultimately, Budyonny's forces marched on Lwów instead of Warsaw, and thus missed the battle.