But even Trotsky condemned acts of terrorism.

Whatever the eunuchs and pharisees of morality may say, the feeling of revenge has its rights. It does the working class the greatest moral credit that it does not look with vacant indifference upon what is going on in this best of all possible worlds. Not to extinguish the proletariat’s unfulfilled feeling of revenge, but on the contrary to stir it up again and again, to deepen it, and to direct it against the real causes of all injustice and human baseness—that is the task of the Social Democracy.

If we oppose terrorist acts, it is only because individual revenge does not satisfy us. The account we have to settle with the capitalist system is too great to be presented to some functionary called a minister. To learn to see all the crimes against humanity, all the indignities to which the human body and spirit are subjected, as the twisted outgrowths and expressions of the existing social system, in order to direct all our energies into a collective struggle against this system—that is the direction in which the burning desire for revenge can find its highest moral satisfaction.