A note on what this article is not: it is not commentary on any current conflict, and it takes no side in one. This site does not do politics. But every generation watches wars, and every tradition we keep here was composed by people who watched them too — several of the texts were written in them. What follows is what they counsel the watcher: not governments, but you.
On hatred as fuel
The Dhammapada's most famous verses were the tradition's first word on the subject: "For hatred does not cease by hatred at any time: hatred ceases by love — this is an old rule" (verse 5). The claim is practical, not sentimental: hatred perpetuates the thing it answers. The Tao Te Ching agrees from the other side of Asia, and goes further — even victory is no occasion for celebration: weapons "are instruments of evil omen", and he who has killed multitudes should "weep for them with the bitterest grief" (chapter 31).
On the peacemaker's task
The Sermon on the Mount places peacemaking among the blessings: "Blessed are the peacemakers, for they shall be called children of God" (Matthew 5:9) — and the Hebrew prophets supplied the image every peace movement since has borrowed: "they shall beat their swords into plowshares... nation shall not lift up sword against nation, neither shall they learn war any more" (Isaiah 2:4). The Psalms make it a personal instruction: "seek peace, and pursue it" (Psalm 34:14) — pursue, as if it runs. And the Qur'an states the arithmetic of a single life: whoever kills an innocent soul, "it is as if he had slain mankind entirely; and whoever saves one — it is as if he had saved mankind entirely" (Qur'an 5:32).
On acting without being consumed
The Bhagavad Gita is set on a battlefield precisely because its question is hardest there: how to act rightly in a broken situation without being poisoned by it. Its answer — act from duty, without hatred and without claiming the fruits — is developed across the whole text (read it verse by verse; our theme page sets it beside the other traditions). Marcus Aurelius, writing his Meditations in an army camp on an actual frontier, reached the companion conclusion: we are "made for cooperation, like feet, like hands", and to act against one another "is contrary to nature" (Meditations 2.1).
On keeping your own heart
What all eight counsel converges on the watcher's inner state: grieve what is grievous (the Tao's instruction is literally to mourn), refuse the pull of hatred (Dhammapada), do the good within reach (the hadith of the Prophet: whoever sees a wrong should change it with his hand, his tongue, or at least his heart), and guard the mind that consumes the news — the restless mind has a theme page of its own. None of the texts asks the watcher to feel nothing. All of them refuse to let the watcher become what they are watching.
Related
The Golden Rule in every tradition · On anger · What prophecy is for