wagons full of war spoils, and fleeing civilians, out of immediate danger. The army experienced losses in life and equipment, but broke out of the entrapment by 16 June. However, contrary to Piłsudski's expectations, it was unable to launch successful counterattacks. In the following weeks, the 2nd and 3rd Armies fought the Bolshevik forces on many occasions. Initially, the strength of their resistance and determination surprised Budyonny and his commanders. On 26 June, Rydz-Śmigły replaced Listowski as commander of the Ukrainian Front, but the Polish armies kept retreating and suffering losses. As they had lost their strategic initiative, the morale of the Polish and Ukrainian soldiers deteriorated and with time their units had become more inclined to surrender. Despite the strength of the Polish artillery formations, the officer corps in particular was subjected to heavy losses, in part due to the continued attempts to launch counterattacks. The Polish 7th Air Escadrille, known also as the Kościuszko Squadron, manned largely by American pilots, was particularly helpful. In late May and early June, they flew many bombing and reconnaissance missions. They slowed the Soviet counteroffensive and the commandant of the Polish 13th Infantry Division commented: "Without the American pilots we would have been long gone". Their machine gun attacks held back the progress of Budyonny's cavalry. The squadron's leading pilot, Merian C. Cooper, was shot down and imprisoned by the Russians, but escaped after two months. After the 16 to 18 August intense fighting in the Lviv area, the fourteen planes of the squadron were credited again with stopping Budyonny and saving the situation. The Polish 3rd Army withdrew to the Styr River line, the 6th Army to the Zbruch River. On 5 July, Brigadier Marian Kukiel wrote: "In the afternoon, we were hit by the unexpected order to retreat to the Zbruch. Depressing news announcing a lost war, or at least a lost campaign". On 19 July, the Poles engaged a substantial Soviet force and fought the enemy for two weeks, which culminated in the Battle of Brody and Berestechko (29 July–3 August). The offensive battle was terminated by Piłsudski, who withdrew two Polish divisions and sent them north, one to strengthen the force concentration at the Wieprz River and one to defend Warsaw. The town of Brody was kept by the Polish forces. Budyonny complained of his Cossacks being stretched to their limits and exhausted, lacking food and feed for