The polar opposite of Luke O'Neill in A Thousand Splendid Suns is Tariq. In The Thorn Birds, Luke is presented as an arrogant, self-centered and selfish man, who cares only about himself. He is greedy, insensitive and power-hungry and marries Meggie to gain access to her land and her money. He shows no affection towards his wife and his child—he treats Meggie like an object and stops her from enjoying her life, and he's indifferent to his daughter Justine, and he doesn't want to see her. Eventually, Meggie decides to leave him; she takes Justine and returns to Drogheda.
Unlike Luke, Tariq is kind, compassionate, and caring. He is described as someone who is capable of feeling great empathy and who isn't afraid to fight for those he loves. He even stands up for his beloved, Laila, and defends her from her bully, despite his physical handicap. Tariq shows his loyalty when he promises to come back to Laila after fleeing with his parents to Pakistan. Years later, he keeps his promise and returns home, only to find out that Laila has married Rasheed. Tariq doesn't hold any prejudice against Laila's choices, however, and understands her motivations.
In the end, Tariq marries Laila because he loves her and because she loves him, and he treats her with all the respect and kindness that she deserves. He loves both his own child and Rasheed's child equally and promises to take care of his family and to support all of their dreams and aspirations.
Thus, Tariq is the polar opposite of Luke, as unlike Luke, who's incapable of loving anyone but himself, Tariq is everything a father and a husband should be.