Nevertheless, Alexei does show passion in his desire for revenge. He wants Anna to return to him but not without consequences.
Not longer jealous, Alexei has progressed to vengeful. A restoration of the family unit is not enough for him. Anna needs to understand the enormity of her actions. His lust for revenge is comparable to her lust for passion, though her lust is forgivable in that she tried to fulfill it in the context of marriage before pursuing the affair with Vronsky. Alexei wants to see Anna suffer, showing he has no understanding of the internal struggle that led to the affair. Alexei is an exterior person, and as long as the exterior appears good, the interior is unimportant. Alexei is unable to see his own motive in wanting to see her suffer because his vision only allows him to view the surface actions, without penetrating further.
Nevertheless, Tolstoy establishes early on that revenge is not for the human scope but God's. Though human nature craves suffering for wrongs inflicted, man does not decide another's punishment. So what is man's responsibility? Forgiveness. Alexei's desire for revenge and his inability to forgive Anna ultimately plays a significant role in her downfall.