How Latin America helped drive nuclear non-proliferation

J. Luis Rodriguez and Elizabeth Mendenhall outline how Latin American states worked with Cold War superpowers to create a nuclear weapon-free zone.

Interview Published 30 June 2022 4 minute READ

As the world approaches the 50th anniversary of the Cuban missile crisis, the threat posed by a potential nuclear exchange continues to loom over contemporary international relations. But although the events which led to nuclear escalation in October 1962 are well-known, the work of Latin American states to make Latin America and the Caribbean a nuclear weapon-free zone in the aftermath of the crisis is often underappreciated.

In this interview, J. Luis Rodriguez and Elizabeth Mendenhall discuss their new article in International Affairs, highlighting the key role developing countries can play in advancing nuclear non-proliferation, and calling into question assumptions that the international nuclear order is solely a product of the world’s most powerful countries.

In your article, you highlight the role played by Latin American states in denuclearizing the region in the aftermath of the Cuban Missile crisis. What were the key features of this process?

The sudden and obvious risk of a regional nuclear war in the aftermath of the Cuban missile crisis made Latin American governments aware of the need to design limits on nuclear arsenals. As a result, they produced the first nuclear weapon-free zone in a densely-populated area, which was designed to reduce the risk of a nuclear war in Latin America and make any such conflict less catastrophic for the region.

After much negotiating, the Cold War superpowers accepted commitments to respecting the region’s non-nuclear status and to sharing nuclear technologies for peaceful uses, especially related to economic development

It took Latin American negotiators less than five years to open the Treaty for the Prohibition of Nuclear Weapons in Latin America and the Caribbean – commonly known as the Treaty of Tlatelolco – for signatures on February 14, 1967. It entered into force on April 22, 1968.

Although Latin American governments renounced their prerogatives to build, acquire, and store nuclear weapons, they knew an agreement among states without nuclear arsenals could not effectively reduce nuclear risks. So they set out to gain the participation of nuclear weapon states.

After much negotiating, the Cold War superpowers accepted commitments to respecting the region’s non-nuclear status and to sharing nuclear technologies for peaceful uses, especially related to economic development. They also provided negative security assurances, agreeing to never threaten or use nuclear weapons against the signatories of the Treaty of Tlatelolco. Latin America secured the hitherto relatively elusive support of nuclear weapon states for regional nuclear arms control and nonproliferation mechanisms.

How did Latin American states resist pressure from the superpowers during these negotiations?

Building international law is a process marked by compromise and concessions from all those involved. This need for compromise opened spaces that Latin American states used to resist pressure and to gain concessions from nuclear weapon states during the Tlatelolco negotiations.

However, for the agreement to work, nuclear weapon states needed to accept restrictions on their nuclear weapons deployments and tests, which allowed them to functionally veto treaty drafts they did not like.

The primary Latin American negotiating strategy to resist pressure from the superpowers was to form a common bargaining front. But such efforts were initially hampered by a lack of agreement in certain areas, especially over several delegations’ attempts to formulate limits on the movement of nuclear weapons by sea through the region during the negotiation despite US opposition.

As a result, Latin American officials excluded such a ban from Tlatelolco, but not because they stopped caring about the issue or simply wanted to gain US support as it may first appear. Rather, they avoided the subject to form an effective common negotiating front on the issues they could agree on.

This shifted the talks about limiting maritime nuclear transit to a wider emerging global process of designing ocean governance rules. During negotiations on what would become the UN Convention on the Law of the Sea (UNCLOS), Latin American countries linked this issue to other ocean governance topics as a way of pushing for a wide-ranging international framework which gave them multiple opportunities to advance their own interests.

Approaches to understanding nuclear politics often assume only the most powerful actors have the capacity to effect nuclear order. How does your research challenge this?

The Latin American construction of a nuclear weapon-free zone questions the assumption that only powerful actors influence the global nuclear order. After the Cuban missile crisis, Latin American governments identified that nuclear and non-nuclear weapon states shared a common goal and took advantage of this window of opportunity to actively design nuclear limits and craft institutions to enforce them.

If the focus was only on the most powerful actors, it would be easy to conclude that nuclear powers shaped the Latin American nuclear weapon-free zone as they were the only countries with nuclear capabilities. But Latin American concessions in making the Treaty of Tlatelolco were not impositions from nuclear powers.

The Latin American construction of a nuclear weapon-free zone questions the assumption that only powerful actors influence the global nuclear order

Their compromises were strategic decisions which helped them promote their governance preferences. By deliberately leaving certain topics off the negotiating agenda, Latin American policymakers were able to form a united negotiating bloc and achieve shared objectives.

Latin America embarked on a laborious process of setting security priorities, crafting compromises, and securing the cooperation of nuclear powers. However, nuclear weapon-free zones are a nuclear nonproliferation mechanism that international relations scholars and policymakers often overlook, and academics and practitioners tend to minimize the role of non-nuclear weapon states and the nuclear governance tools they design.

In this context, the Treaty of Tlatelolco reminds the world that the commitments of non-nuclear weapon states are fundamental to maintaining the global nuclear order.

What are the main legacies of these negotiations?

The main legacy of the Treaty of Tlatelolco is its direct – and highly successful – prohibitions on nuclear weapons in its zone of application. The treaty is also remarkable for its significance as a model for subsequent nuclear weapon-free zones, a fact well-recognized by diplomats and scholars alike.

The ambition and design of the agreement inspired other regions to negotiate nuclear weapon-free zones on their own terms, although with less success at convincing nuclear weapon states to ratify their protocols.

The choice of the Latin American states to shift the issue of maritime nuclear transit to the Third Conference on the Law of the Sea also impacted the emergence of UNCLOS, albeit in a more ambiguous way.

Shifting discussions of maritime nuclear transit to this global forum meant the specific rules were finalized in the context of a far more complex network of interests, linkages, and deals. Although the Latin American group was influential during the UNCLOS negotiations, nuclear transit was both subsumed within the wider topic of maritime transport and somewhat deprioritized in relation to the treaty’s economic components.

In the end, international law around maritime nuclear transit now exists but remains sufficiently vague to allow countries to legally justify both restricting and allowing maritime nuclear transit.

What lessons can be taken from Latin American denuclearization when trying to understand challenges facing contemporary nonproliferation efforts?

Non-nuclear weapon states and developing countries have agency and can employ diplomatic strategies on a regional basis which strengthen their influence relative to nuclear weapon states. But the approaches available depend in part on the rest of the governance landscape.

The existence of parallel negotiation forums is an important condition for the diplomatic approach our articles highlights of bracketing away contentious issues to ensure achievable policy consensus.

How Latin America helped drive nuclear non-proliferation 2nd part

Denuclearization proponents can still look to other forums, but the ocean governance regime is in a vastly different state than it was during the 1960s and 1970s, and therefore may make this tactic less effective. The more crowded governance landscape of the 21st century is a challenge for this approach.

There are other possible forums to which some portions of denuclearization efforts could theoretically shift – such as the evolving regimes for international trade, environmental protection, and outer space. Our research highlights how shifting divisive issues to other forums can reduce conflict within regional coalitions.

But these alternative forums could also be framed more positively as options through which targeted regulations and restrictions could be negotiated. In either case, consensus positions adopted by coalitions of non-nuclear weapon states remain critical to constructing new arms control and nonproliferation agreements.