In plain words
That is action free of self-interest. They are actions done for the welfare of the world. They are sacred actions that show society its ideal. To show the ideal to fellow human beings, God too enters into small matters and gives endless teaching. So God shows humility and obedience. When the time comes, He speaks without mercy, and harshly too. He sets out the truth plainly, as it is.
After the war Dharmaja resolved to perform the Rājasūya sacrifice. All the people agreed to it. The gurus Vaśiṣṭha and Viśvāmitra agreed as well. All the ṛṣis consented to this Aśvamedha sacrifice. But whatever small task they had resolved on, they were people who could not do it without Kṛṣṇa's grace. Dharmaja waited for Kṛṣṇa's command; he sent Arjuna and called Kṛṣṇa to him. He set out his wish clearly. Kṛṣṇa laughed: "Brother-in-law, this is not fitting for you. Only a king who holds sole sovereignty under one umbrella has the right to perform this Aśvamedha. You are not the sole sovereign. There are still some kings stronger than you. Śiśupāla, Dantavaktra, Jarāsandha: there are all these. While kings of such great might are there, you have no right at all to perform the Aśvamedha sacrifice," He said firmly, and tried to stop him. At every moment Kṛṣṇa is the embodiment of Satya, who teaches with an eye to the time, the deed, the cause and the duty. "If you truly wish to perform the Rājasūya, conquer these three kingdoms," He said. Taking hold of words like these, people went about telling and explaining that Kṛṣṇa was a man mad for war. What Kṛṣṇa said was not "Make war". He told him to gain the right fit for the Rājasūya. Then Dharmaja, together with his brothers, conquered Śiśupāla, Dantavaktra and Jarāsandha.
In statecraft too we must consider Kṛṣṇa's ideal well. Dharmaja began the Rājasūya sacrifice. To each brother he gave charge of one task. But at that time Kṛṣṇa too came to Dharmarāja and stood with His hands folded. "Dharmaja! By the way of the world, you are the sovereign. I am one who lives under your rule. So give Me some service to do," He asked. These words that Kṛṣṇa spoke caused Dharmarāja some pain. "That Kṛṣṇa, who knows all, pervades all and is all power, should ask such a thing! Kṛṣṇa, is this kingdom not Yours? Am I not Yours? Everything has come to me through You alone. So You alone are the king. I am a small, lowly one within it," he said. "Dharmaja! What you say is true in Bhakti and surrender. But in the affairs of the world one must follow only the rules of statecraft," He said. Even in those days there were some rules that belonged to divinity and some matters that belonged to humanity.