UN Secretary-General António Guterres warned on 28 February that joint US-Israeli strikes on Iran, followed by Tehran’s retaliatory attacks across the region, pose a “grave threat to international peace and security.” He urged all parties to prevent a wider Middle East war, warning the violence could trigger “a chain of events that no one can control” in an already volatile region. Stressing the UN Charter’s prohibition on the threat or use of force and the need to respect international and humanitarian law, he called for an immediate de-escalation, protection of civilians, and nuclear safety. Guterres said the military operation came amid indirect US-Iran talks mediated by Oman, “squandering” an opportunity for diplomacy, and pressed parties to return to negotiations, including on Iran’s nuclear programme. Council members voiced sharply divergent positions, with Russia and China condemning the strikes, the United States defending them as necessary to curb Iran’s missile and nuclear ambitions, the UK emphasizing regional defensive operations, and Iran and Israel offering opposing legal and security justifications.