On March 5, the world will celebrate the 50th anniversary of the entry-into-force of the Treaty on the Nonproliferation of Nuclear Weapons (NPT). In honor of this occasion, let’s look back and reflect upon what is the NPT, why it was created, and what makes it arguably the most successful Treaty of the twentieth and twenty-first centuries.
What is the NPT?
The NPT has become the basis for states to work together to halt the spread of nuclear weapons. States with nuclear capabilities formed the NPT to prevent the further spread of nuclear weapons to non-nuclear weapon states, who, in turn, commit to never acquire them. All NPT Parties agree to pursue negotiations in good faith on disarmament and to share in the benefits of peaceful uses of nuclear energy and technologies.
This last element advocates for cooperation in developing and exploring peaceful uses of nuclear energy. Peaceful applications range from innovations in health care, water safety and management, and food security, to maintaining nuclear security and safety procedures. Nuclear energy has also proved valuable for environmental protection. For example, Senegal has used nuclear science and technology to prevent the tsetse fly from spreading disease, harming cattle which provide essential meat and milk, and damaging agriculture by reducing crop production and food supply. Overall, nuclear energy is a reusable, non-finite fuel source that can improve livelihoods around the world, so furthering its use is important to many in the international community.
Why was it Created?
The emergence of nuclear weapons forever changed modern warfare, and the NPT was negotiated in response. While the United States, United Kingdom, and Soviet Union were the only states capable of conducting a nuclear detonation in the 1940s and 1950s, the international community was afraid that Cold War tensions would erupt into a full-scale nuclear war with devastating consequences. The prospect of mutually assured destruction was a strong incentive to avoid nuclear war, but it did not prevent a rise in great power competition, as nuclear weapons became more powerful and state arsenals continued to grow. Concerns about the risk of nuclear war placed increasing pressure on the international community to find some way to stem the further spread of nuclear weapons and to address rising tensions. The answer was the NPT.

The concept behind the NPT was brought to the world stage on November 28th, 1961, at a meeting of the United Nations General Assembly. The General Assembly adopted a resolution, put forward by Ireland, recognizing that the full cooperation of nuclear and non-nuclear weapon states would be needed to halt further proliferation of nuclear weapons. At first, progress seemed impossible. The differing political goals of the United States and the Soviet Union, as well as disagreements between nuclear and non-nuclear weapon states, brought discussions to a standstill.
It was not until 1965 that truly substantive negotiations began, led by the United States and Soviet Union as co-chairs of the Eighteen Nation Disarmament Committee in Geneva. Nations of the east and west, north and south came together and made concessions. At last, on July 1, 1968, the NPT was crafted and ready to sign.
On March 5, 1970, it was ratified by 44 states and entered into force. By 1980, over 100 states had ratified the NPT. The Treaty provides for signatories to gather every five years for a Review and Extension Conference to hold discussions on the Treaty’s operation to assure that its purposes and provisions are realized. At the NPT’s May 1995 Review Conference in New York City, the Treaty was extended indefinitely, as Parties recognized the importance of the NPT to international peace and security.
Today, NPT adherence has grown to nearly 200 Parties, making it the most widely adhered to nuclear agreement in history.

Why is the NPT Considered One of the Most Successful Treaties?
The NPT was a multilateral Treaty created at a time of increasing hostility between the United States and Soviet Union—now Russia—and as other states were seriously pursuing nuclear weapons or capable of doing so. The NPT has helped the world avoid nuclear war, prevented a predicted cascade of non-nuclear states from acquiring their own nuclear weapon stockpiles, and locked in commitments to nonproliferation, disarmament, and peaceful use of nuclear energy.
The 50th Anniversary of NPT is therefore not only a celebration of the Treaty, but also of states coming together for the common good of fostering a more stable and prosperous world during a period of extreme tension. Whether by easing Cold War tensionsfurthering the efforts of nonproliferation and disarmament, or by spreading the benefits of the peaceful uses of nuclear technology to every corner of the world, the NPT has changed the discourse on nuclear weapons forever.
Eleni Zervos serves as an intern for the Bureau of International Security and Nonproliferation at the U.S. Department of State.