The Russian invasion of Ukraine has brought back the spectre of nucle-ar war. A sustained nuclear “sabre-rattling” from Russian authorities has triggered a dynamic debate about the Russian nuclear doctrine, the feasibility of use of “tactical” nuclear warheads in the Ukrainian battle theatre, the alleged consequences of such use, including esca-lation to a wider nuclear exchange with the United States and NATO, and the impact of such developments in global peace and security. The alarming prospect of nuclear devastation requires a bold politi-cal response from all peace-loving nations, particularly those from the South, cooperating with United Nations members coalescing around the Treaty on the Prohibition of Nuclear Weapons (TPNW) and, more widely, in like-minded coalitions galvanized by the humanitarian con-sequences of nuclear detonations. The Latin American and Caribbean region, and Chile in particular, have a special responsibility to deploy their diplomatic capabilities, inter alia, by supporting the Secretary General’s “New agenda for peace”, and mobilising the normative and operational powers of the General Assembly.