Electrostatic Forces of Plasma Dust Grains with Position-Dependent Charges

In a recent study [V.N. Tsytovich, Comments Plasma Phys. Controlled Fusion 15, 349 (1994)], Tsytovich claims that two negatively charged particles can attract each other if the particle charges decrease as the distance between the two particles decreases. In this article I show the energy analysis by Tsytovich is erroneous and the electrostatic force between two like-charge particles immersed in a quiet background plasma is always repulsive. Attractive forces between such particles, if exist, therefore must be attributed to other mechanisms.