By late autumn 1919, many Polish activists from different political formations concluded that Poland, generally successful in pushing the Red Army forces to the east and gaining territory there, should now pursue peace by negotiating with Soviet Russia.

The National Democracy politicians had hoped that talks with the Soviets would derail the plans for Józef Piłsudski's alliance with Symon Petliura and resumption of the war with Russia, which they opposed.

National Democrats did not believe that poor and relatively weak Poland was capable of carrying out Piłsudski's objective of building and leading an anti-Russian federation of states.

[4] Following fruitless exchanges with Foreign Minister Stanisław Patek, after 7 April Chicherin accused Poland of rejecting the Russian peace offer and heading for war; he notified the Allies and called on them to restrain the Polish aggression.

[16] In exchange for agreeing to a border along the Zbruch River,[16] Petliura was promised military help in regaining Soviet-controlled Ukrainian territories, including Kiev.

He had become convinced that the Russian White movement and its forces, largely defeated by the Red Army, were no longer a security threat to Poland and that he could take on the remaining adversary, the Bolsheviks.

The weakness of the enemy had supposedly offered a unique opportunity for Poland, one that should not be missed, especially given the exceptional abilities of Commander-in-chief Piłsudski and the strength and fitness of the Polish Army.

Foreign Minister Stanisław Patek headed for Western Europe to explain to the Allies the rationale behind the offensive Poland undertook and to seek new shipments of military supplies.

In a 26 April letter to Prime Minister Leopold Skulski, Piłsudski characterized the Bolshevik formations as "almost incapable of any resistance", strongly impressed by the extraordinary speed of Polish moves.

[31] The military and political developments elicited a sharp response in Russia, where Vladimir Lenin and Leon Trotsky appealed to national sentiments and called for total war with expansionist Poland.

General Aleksei Brusilov, former chief commander of the Russian Empire's Tsarist army and from 2 May chairman of the new Council of Military Experts, appealed to his former officers to re-enlist with the Bolshevik forces and 40,000 of them complied.

[34] What appeared to be a highly successful military expedition to a city that symbolized the eastern reaches of Polish history (harking back to the intervention of Bolesław I the Brave in 1018) caused enormous euphoria in Poland.

On 18 May in Warsaw, he was greeted in the Sejm by its Marshal Wojciech Trąmpczyński, who spoke of a tremendous triumph of Polish arms and said to Piłsudski: "The victories of our army accomplished under your leadership will influence the future in our east".

[35] On 26 April in Zhytomyr, in his "Call to the People of Ukraine", Piłsudski assured that "the Polish Army would only stay as long as necessary until a legal Ukrainian government took control over its own territory".

[38][39] Actions such as punitive military expeditions organized by Polish land owners against rebellious Ukrainian peasants strengthened the effectiveness of Bolshevik propaganda.

Józef Jaklicz, chief-of-staff of the 15th Infantry Division, wrote to his wife on 30 May: "We have overestimated our strength and threw ourselves into politics on a grand scale, with the military engaged, without being properly secured ...

[34] According to the concept of Boris Shaposhnikov, chief operations manager on the Field Staff of the Revolutionary Military Council, the Soviet leadership decided to concentrate forces in Belarus and launch a counteroffensive from there.

[43] Western Front's 15th and 16th Armies attacked the slightly weaker Polish forces (the combatants had respectively 75,000 and 72,000 combined infantry and cavalry soldiers at their disposal) and penetrated the Polish-held areas to the depth of one hundred kilometers.

[28][43] Because of the energetic Polish counter-offensive led by Stanisław Szeptycki, Kazimierz Sosnkowski and Leonard Skierski, by 8 June the Poles had recovered the bulk of the lost territory, Tukhachevsky's armies were withdrawn to the Avuta and Berezina Rivers, and the front had remained inactive until July.

While Tukhachevsky retained control of the strategic points needed for future offensive action, the Polish high command kept its ineffective system of linear arrangement of forces and weak rear reserves.

To Piłsudski, Budyonny's horse people were like bands of nomads or swarms of locusts (a reference to their propensity to wreak havoc on civilian communities encountered), incapable of executing any effective cavalry charge.

[44][45] Alexander Yegorov, commander of the Russian Southwestern Front, having received considerable reinforcements, initiated on 28 May an assault maneuver in the Kiev area.

The Polish Army evacuation, accomplished over the next few days, was preceded by the destruction of the city's bridges, electric power stations, and water pumps on the Dnieper.

It took considerable military experience and ingenuity to maneuver the army, the trains of wagons full of war spoils, and fleeing civilians, out of immediate danger.

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 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 Russian forces also remained in western Ukraine and become involved in heavy fighting for the area of the city of Lviv, which had been under 1st Cavalry Army's siege from 12 August.

[44][55] The Poles denied that they had committed any such acts of vandalism, claiming that the only deliberate damage they carried out during their evacuation was blowing up the bridges in Kiev across the Dnieper River, for military reasons.

[59] Richard Watt wrote that the Soviet advance into Ukraine was characterized by mass killing of civilians and the burning of entire villages, especially by Budyonny's Cossacks; such actions were designed to instill a sense of fear in the Ukrainian population.

[60] According to Chwalba, "The news of the savagery, brutality and ruthlessness of the cavalry had a paralyzing effect and demoralized a soldier, who constantly looked back, seeking an opportunity to run away or desert.