He became the de facto chief of the Kontrrazvedka, the Makhnovist military intelligence division, and carried out a campaign of terror against the Bolsheviks and the White movement.

[2] After Zadov went to work in the metallurgical factories of Yuzivka, in 1910, he joined a local anarcho-communist group and began to participate in a series of armed robberies, known as "expropriations".

[7] In April 1919, Zadov established sections of the Kontrrazvedka in Mariupol and Berdiansk, which were concerned with securing provisions for the army from the civilian population, either through expropriations or levies.

[9] Following the break between the Makhnovists and the Bolsheviks, and the subsequent retreat to Uman, Zadov became the Kontrrazvedka's chief of staff for the 1st Donetsk Corps of the reorganised Revolutionary Insurgent Army of Ukraine.

[11] As the de facto chief of the Kontrrazvedka,[12] Zadov became infamous in Bolshevik accounts of the Makhnovist conduct in the war,[13] which described him as a "butcher" and a "common criminal",[14] and was even investigated by a commission of the Regional Congress, due to the excesses committed under his command.

[16] When the 1st Donetsk Corps withdrew from Oleksandrivsk on 3-4 November 1919, Zadov's Kontrrazvedka was ordered by Makhno himself to remain behind in the city and to liquidate 80 members of the anti-Makhnovist opposition, including Mensheviks and Socialist Revolutionaries.

[17] Makhno then ordered Zadov to take 30 barrels of liquor and leave them in a nearby village, successfully distracting the pursuing forces of Andrei Shkuro,[18] and to spread word of the Makhnovist offensive, causing peasant uprisings in the rear of the White movement.

[21] This preceded a period of renewed conflict between the Makhnovists and the Bolsheviks, during which two members of the Cheka attempted to recruit Zadov over their side, but they were arrested and shot on 21 June 1920.

[28] In the Romanian capital of Bucharest,[29] Zadov established a Makhnovist Foreign Centre, through which the insurgents aimed to prepare another anti-Bolshevik uprising in Ukraine.

[31] He then crossed back over the Dniester and surrendered to the Joint State Political Directorate (OGPU),[32] which granted him amnesty and recruited him into the Soviet intelligence service.

[30] Zadov worked with the Foreign Centre to organise safe passage for any Makhnovists who wished to return from exile and receive amnesty from the Ukrainian Soviet government.