>Except that Achilles did *not* choose to go to war. On the contrary,
He chose to return to battle to avenge Patroclus, even though the gods warned it wouldn't end well:
The sire of gods and men smiled and answered, "..... tell Neptune to leave off fighting and go home, and Apollo, that he may send Hector again into battle and give him fresh strength..... Achilles will then send his comrade Patroclus into battle, and Hector will kill him in front of Ilius after he has slain many warriors, and among them my own noble son Sarpedon. Achilles will kill Hector to avenge Patroclus, and from that time I will bring it about that the Achaeans shall persistently drive the Trojans back till they fulfil the counsels of Minerva and take Ilius.... "
[...]
Achilles groaned and answered, "Mother, Olympian Jove has indeed vouchsafed me the fulfilment of my prayer, but what boots it to me, seeing that my dear comrade Patroclus has fallen- he whom I valued more than all others, and loved as dearly as my own life? I have lost him; aye, and Hector when he had killed him stripped the wondrous armour, so glorious to behold, which the gods gave to Peleus when they laid you in the couch of a mortal man. Would that you were still dwelling among the immortal sea-nymphs, and that Peleus had taken to himself some mortal bride. For now you shall have grief infinite by reason of the death of that son whom you can never welcome home- nay, I will not live nor go about among mankind unless Hector fall by my spear, and thus pay me for having slain Patroclus son of Menoetius."
Thetis wept and answered, "Then, my son, is your end near at hand- for your own death awaits you full soon after that of Hector."
Then said Achilles in his great grief, "I would die here and now, in that I could not save my comrade. He has fallen far from home, and in his hour of need my hand was not there to help him. What is there for me? Return to my own land I shall not, and I have brought no saving neither to Patroclus nor to my other comrades of whom so many have been slain by mighty Hector; I stay here by my ships a bootless burden upon the earth, I, who in fight have no peer among the Achaeans, though in council there are better than I. Therefore, perish strife both from among gods and men, and anger, wherein even a righteous man will harden his heart- which rises up in the soul of a man like smoke, and the taste thereof is sweeter than drops of honey. Even so has Agamemnon angered me. And yet- so be it, for it is over; I will force my soul into subjection as I needs must; I will go; I will pursue Hector who has slain him whom I loved so dearly, and will then abide my doom when it may please Jove and the other gods to send it. Even Hercules, the best beloved of Jove- even he could not escape the hand of death, but fate and Juno's fierce anger laid him low, as I too shall lie when I am dead if a like doom awaits me. Till then I will win fame, and will bid Trojan and Dardanian women wring tears from their tender cheeks with both their hands in the grievousness of their great sorrow; thus shall they know that he who has held aloof so long will hold aloof no longer. Hold me not back, therefore, in the love you bear me, for you shall not move me."