This study analyzes the relationship between the Makhnovshchina (Makhno movement) and the Bolsheviks in 1920. It focuses on circumstances and factors that led Makhnovists and the Bolsheviks to sign the Starobilsk Agreement, and asks questions about how both sides perceived this agreement, and what their expectations were. It also discusses the ramifications of concluding the agreement and its significance for the subsequent alliance. The relations between the Makhnovshchina and the Bolsheviks can be characterized as ambivalent and dynamic. The relations were based in common interests that consisted of the defeat of the White Army; however, they had different goals, which gradually led to further military confrontation. Unlike the Bolsheviks, who had clear plans for the Makhnovshchina, the Makhnovists lacked a defined concept for developing their movement after the defeat of Wrangel. For the Makhnovists, the Starobilsk Agreement may have been a means to legitimize their movement; however, for the Bolsheviks, it made a convenient means for their liquidation. Thus, paradoxically, in 1920 the Makhnovshchina became an unintentional “long arm” of the Bolsheviks, which indirectly helped them gain control over southeastern Ukraine.