Fifty years ago, the United States was in the midst of a Cold War with Russia. The world was watching nervously as its two superpowers were locking horns in a nuclear arms race. At the same time, nations throughout Latin America and the Caribbean were deciding for themselves that nuclear weapons had no role in their region.
With little fanfare, the Treaty of Tlatelolco opened for signature on February 14, 1967. This landmark treaty led to the establishment of a nuclear-weapon-free zone in Latin America and the Caribbean. This treaty was indeed groundbreaking. For the first time in history, the nations of a populated region joined together to draft an agreement prohibiting nuclear weapons in their territories. From the beginning, the United States strongly supported the Treaty. The world owes a debt of gratitude to the drafters of the Treaty for their innovative thinking and for their extraordinary foresight to understand the dangers posed by nuclear weapon proliferation.

Since then, nuclear weapon-free-zones have come to cover 114 countries in four other regions of the globe. All of these nuclear-weapon-free zones were negotiated on the basis of arrangements freely arrived upon among the States within the Latin America and Caribbean region; the United Nations Disarmament Commission affirmed this principle of zones that arose from dialogue and consensus among the regional states in its 1999 guidelines on nuclear-weapon-free zones. These nuclear weapons-free zones complement the Treaty on the Non-proliferation of Nuclear Weapons and strengthen the norm against nuclear proliferation. We laud this practical and realistic approach to enhancing global and regional peace and security and recognize that such nuclear weapon-free-zones have immeasurably strengthened the global nuclear nonproliferation regime.
The United States demonstrated its commitment to the Treaty of Tlatelolco by becoming a Party to both of the Treaty’s Protocols. As such, the United States pledged not to use or threaten to use nuclear weapons against the Treaty Parties or contribute to the violation of the Treaty’s obligations. We also agreed not test, manufacture, store, or deploy nuclear weapons in U.S. territories within the zone’s territorial limits under this Treaty’s Protocols.
The International Atomic Energy Agency (IAEA) has played an important role in the Treaty of Tlatelolco by establishing comprehensive safeguards agreements with the states of the region. IAEA inspectors verify that all such states are abiding by their commitments to use nuclear material and facilities exclusively for peaceful purposes. Territories of the United States in the Caribbean region are also subject to IAEA safeguards. The peace and security of the States Parties to Tlatelolco, as well as the rest of the world, has been greatly enhanced through the IAEA’s efforts. We urge all States in the region and elsewhere to adopt the highest level of standards for International Atomic Energy Agency safeguards.
By keeping Latin America and the Caribbean free of nuclear weapons and establishing a model for other regions to follow, the Treaty of Tlatelolco gave the world a model for limiting the risks of nuclear war and strengthening regional nuclear nonproliferation. Today is a day to celebrate the wisdom of its drafters 50 years ago and to rededicate ourselves to work together to build on its promise.
About the Author: C.S. Eliot Kang serves as Acting Assistant Secretary of State for the Bureau of International Security and Nonproliferation at the U.S. Department of State.
Editor’s Note: This entry is also published on Medium.com/StateDept .