Achilles, in effort to match his personal loss on a national level, strives to kill Hector, again fueling the economy of revenge, but this time in a far more 'high stakes' manner. Now, the loss of a man will result in the loss of Troy's greatest warrior. But even though Achilles emerges victorious from this struggle, his is an empty victory. He knows that his own death will follow shortly after the death of Hector. He does not care; revenge means everything to him in the heat of the moment, just like sacrificing the Greek advantage was worth upholding his honor at the beginning of the poem.
Although Achilles' sudden loyalty to his friend may seem honorable to some degree, perhaps more honorable than Menelaus' obsession with Helen, it also shows how the dynamic of loss leading to more and greater losses has spiraled out of control. The one real positive action of the poem is not Achilles' revengeful killing of Hector, but the attempted mending of the anger Achilles feels towards Hector even after Hector's death by Priam. At night, Priam bravely and humbly begs Achilles to return the body of his son. Priam comes, not as a king to the tent of the great warrior, but as someone who has lost a dear, beloved person to war.
This is why Achilles is sympathetic to Priam, unlike his behavior towards Agamemnon. Now Achilles understands loss more deeply, and more meaningfully, than he did when he first agreed to go to Troy and seek glory rather than a long life. Priam, as a man who has known and suffered loss, rather than shut himself away from the consequences of his loss like Agamemnon, who fled the circumstances he left at home after the loss of his daughter, provokes sympathy in Achilles. The epic ends with the sight of two people who have suffered losses together, from opposing, supposedly enemy sides. Even though Achilles has killed Priam's son, he is still able to sympathize with and mourn with Priam, because both men appreciate the terrible dynamic of war and loss that begin with the loss of spoils, women, and beauty, and now has lead to the losses of the best of men.
If the "Iliad" denied the need for war entirely on a societal level, then the ravings of ugly men who encourage mob revolt and departure, would be validated. The need for defense is acknowledged by the structure of the text, and Achilles' refusal to fight has negative rather than positive results. The amoral gods make sure that the fight continues, and cannot be resolved by either peaceful diplomacy or even more limited action at the hands of the suitors of Helen. But by structuring the text as he does, the poet Homer makes a poem that is a testimony to war, also a powerful anti-war epic, as it begins and ends with morally ambiguous situations where the lines between enemies are blurred. The book begins with a quarrel between to supposed allies, and ends with peace between two men who are still technically enemies, both of whom are contemplating their own likely deaths in the coming months or years.
Homer's "Iliad" was later to inspire dramatic works that dealt with the familial aftermath of war, such as "Iphiegnia at Aulis" and "Agamemnon," which show the folly of Agamemnon's actions, resulting in the infidelity of his wife and both of his daughter's isolation and misery from her family. The saga shows how war disturbs and fractures the family. Even Odysseus, the most emotionally stable and clever of all of the Greek warriors, mourns his lost kingdom, wife, and home, while he fights on. The constant cycle of blood and displacement is never-ending, and is mitigated only slightly by forgiveness, as Patroclus and Hector are finally given fitting burials.
Burials do not lead to the end of death -- Patroclus' death leads to the death of Hector, and Hector's burial will really mark Achilles' own death. Achilles actions are inhuman and against the moral, human laws of war, and circumvent the cycle of death, burial, and rebirth by preventing Hector from going to the underworld and enjoying the lands of the warriors below. But even after he changes his mind and shows compassion, to Priam Achilles cannot prevent his own death, or end the cycle of war.
Moderns often, see war seen as justified or unjustified, good or evil. The "Iliad" provides a powerful, instructive text of a the moral view of Greek society that saw war as evil and immoral, yet also as necessary in a land of fractured and quarreling city-states, and where a man's reputation was dependant upon his military might. Even the devaluation of women may be partly rooted in a male mistrust of persons who are non-combatants. War is life, for the Greeks, but that does not mean war is good.