Diomed looked sternly at him and said, “Hold your peace, my friend, as I bid you. It is not amiss that Agamemnon should urge the Achaeans forward, for the glory will be his if we take the city, and his the shame if we are vanquished. Therefore let us acquit ourselves with valour.”
~ The Iliad - Book 4 (Samuel Butler Translation. p28 / v411)
The Iliad - Book 4. The gods especially Juno, wants war. Minerva makes Pandarus shoot a bow on Menelaus who gets injured. War is declared since Trojans violated their oath.
In book 4 of The Iliad, Agamemnon goes over to every group in his army and either praises or chides them. He praised them if he felt they were ready and raring to fight and scolded them if he thought they were not interested or slacking. He gets it wrong a few times - especially with Ulysses and the son of Capaneus. Was it a good strategy, I wonder. The war had already started, and did people need to be reminded?