The Devil's Double

In 1987, Latif Yahia (Dominic Cooper), an Iraqi soldier fighting in the IranâIraq War, is called to become a "fedai" ("body double" or political decoy) for Uday Hussein (also played by Cooper), the playboy son of Iraqi president Saddam Hussein (Philip Quast). Latif comes from an upper-class family and had attended school with Uday, where the other students would remark on their likeness. Latif initially refuses the position, but is imprisoned and tortured, ultimately relenting when his family is threatened. Latif undergoes minor cosmetic surgery to perfect his resemblance to Uday and practices emulating the young Hussein's mannerisms and wildly volatile persona. He is given access to all of the luxurious benefits of the Husseins' fortune, including massive palaces, expensive wardrobes and Uday's Ferrari and various other exotic cars. Latif tries to resist Uday's exorbitant merrymaking and erratic behavior, at one point fleeing a nightclub in another of Uday's Ferraris to attempt to see his family, who believe he has died in the war. However, he is apprehended by Uday's bodyguards and given a whipping by Uday. After an appearance at a conference with several Kuwaiti leaders, an attempt is made on Uday's (Latif's) life, apparently by a member of a rebel opposition group, possibly a Kurd. The real Uday, though, is more concerned with the Kuwaitis, who he believes have been slant drilling into Iraq's Rumaila oil field. The First Gulf War is launched with Uday proclaiming "The Age of the Sheikhs is over!"
Uday's increasingly violent, sadistic tendencies are displayed when he kidnaps a 14-year-old school girl and forces her to escort him to a party. At the party, based on an actual 1988 celebration honoring Egyptian President Hosni Mubarak's wife Suzanne, Uday becomes enraged with his father's personal bodyguard Kamel Hana Gegeo (Mehmet Ferda). Uday believes Gegeo facilitated an affair between Saddam and Samira Shahbandar, which devastated his mother, Sajida Talfah, and he also expresses jealousy at the trust his father places in Kamel Hana. When Gegeo passes sarcastic comments about Uday's sexual advances towards his young victim, Uday butchers him with an electric carving knife in front of all of the guests. The next morning, Uday's bodyguards are seen dumping the partially naked, beaten body of the young girl.
Latif, acting as Uday, is later sent to Basra to rally support among Republican Guard soldiers as Coalition forces have taken control of the war. At Basra, another attempt is made on Latif's life. To Uday's great concern, Latif nearly loses a little finger in the assault, which presumably would mean Uday would have to have his amputated to maintain their resemblance, but doctors are able to save Latif's finger. Later, Latif is confronted by the father of the young girl Uday killed. Uday eavesdrops on the conversation and is outraged by the man's pleas for "justice" and "compassion." Uday orders Latif to kill the man, but Latif refuses and instead slits his own wrists, to Uday's amusement. After Latif recovers, he confronts Uday at his birthday party. The confrontation escalates to a shootout and Latif escapes in Uday's Mercedes with Uday's lover, Sarrab (Ludivine Sagnier). The two escape to Valletta, but Sarrab, fearing for her daughter in Iraq, calls Uday begging for the chance to return without being harmed. A would-be assassin sent by Uday just misses shooting Latif almost as soon as they arrive on the island. Uday calls Latif and offers him one final chance to return to Iraq, threatening to kill his father if he refuses. Latif's father encourages him not to return and he is killed.
However, Latif does return to Iraq, not to continue to serve as Uday's double, but rather to kill him, with the help of a man whose bride killed herself after being raped and beaten by Uday on her wedding day. In an adapted version of the attempt on Uday's life made by the 15th Shaaban in 1996, Latif and his partner ambush Uday while he is attempting to lure young girls into his Porsche. They wound him severely, including mangling his genitals with a direct shot. One of Uday's bodyguards catches up to Latif as he flees the scene. The guard, however, is one who Latif could have killed as he fled from Uday's birthday party before leaving the country but spared, and the guard extends him the same courtesy.
The movie ends by stating that Latif has been a very difficult man to find after these events. (Though apparently once spotted in Ireland with wife and two children.) Uday was permanently handicapped by the attack but survived until his killing by the U.S. forces in 2003.

Question: Why does Latif return to Iraq?
Answer: To kill Uday