Zeus abandons the Trojan war once Hector and his Trojans start fighting for the ships. The father god isn't entirely omniscient; he doesn't predict that the other gods will attempt to thwart his will.
[Spoiler (click to open)]Disguised Poseidon urges the Argives on. "His voice like a shock wave, / the god of the earthquake"
Corpses fall like trees. Fighters struggle over plunder. The fight becomes more personal when the sea god's grandson is killed. Basically, the Greeks are still awesome and were only doing poorly because of Zeus' intervention. I suspect Homer's audience was primarily patriotic Argives who wouldn't want to hear about their ancestors losing too badly.
Idomeneus and Meriones discuss cowardice versus bravely briefly before returning to the fight. The skin of the coward changes color all the time,
He can't get a grip on himself, he can't sit still, he squats and rocks, shifting his weight from foot to foot, his heart racing, pounding inside the fellow's ribs, his teeth chattering-he dreads some grisly death. But the skin of the brave soldier never balances. He's all control. Tense but no fear. The moment he joins his comrades packed in ambush
he prays to wade in carnage, cut-and-thrust at once.
The narrator doesn't seem to fully agree with Idomeneus. Often brave warriors do feel and show fear. For all its trumpeting of glory and bravery, the poem acknowledges that As gale-winds swirl and shatter under the shrilling gusts
on days when drifts of dust lie piled thick on the roads and winds whip up the dirt in a dense whirling cloud- so the battle broke, storming chaos, troops inflamed, slashing each other with bronze, carnage mounting, manslaughtering combat bristling with rangy spears, the honed lances brandished in hand and ripping flesh and the eyes dazzled now, blind with the glare of bronze, glittering helmets flashing, breastplates freshly burnished, shields fiery in sunlight, fighters plowing on in a mass. Only a veteran steeled at heart could watch that struggle
and still thrill with joy and never feel the terror.
Particular battle at this moment has more to do with the rivalry of Poseidon with Zeus. Both gods knotted the rope of strife and leveling war,
strangling both sides at once by stretching the mighty cable,
never broken, never slipped, that snapped the knees of thousands.
Here's the other non-Paris reason for fighting that I remembered earlier: Othryoneus fights for the privilege of marrying Priam's daughter Cassandra. He dies.
Deiphobus pulls Aeneas into the fighting. Aeneas was idle, angry at Priam for scrimping on his honors. (What is with these people?) Aeneas vs. Idomeneus and their comrades
Menelaus fighting: The narrator recalls how personal this is for him and implies that he doesn't think Helen left willingly.
Paris kills Euchenor, son of the prophet Polyidus. Euchenor was able to choose between two deaths-slowly succumbing to a plague or death in battle. Also, Euchenor is practical and joined to avoid the Argive fine for desertion. Another reason for so many Argives to accompany the stubborn, selfish Agamemnon in his brother's personal quarrel.
Unaware of the Poseidon-backed carnage, Hector rampages on. Polydamas advises that they pause and plan a more strategic assault. Hector, seeing a chance for "less danger, more success", assents. Surveying the damage, Hector takes an opportunity to taunt Paris. It's like his hobby. Paris' reply: I'm not behaving like a coward today.