What international legal, guarantees would an Iran-US memo carry?
By Hossein Sadat Meidani
Professor of International Relations
Iran and the United States, with mediation from Pakistan, Qatar and several other countries, have reached a memorandum that outlines a framework for ending the current hostilities and steering future diplomatic talks toward a comprehensive agreement. The document is scheduled to be signed in Geneva on June 19.
From an international law perspective, the most important question is the legal nature of this document. Separate from any analysis of the specific obligations and responsibilities that may arise for each side, which itself requires a dedicated legal examination, several observations can be made about the character of the memo.
Distinguishing between non-binding document and its legal effects
Contemporary international law draws a clear distinction between the non-binding nature of an international document and its legal consequences. Labeling a document as political or non-binding does not automatically mean it is devoid of international legal effects for the parties involved.
The issue has become significant enough that, since 2023, the United Nations International Law Commission has placed the study of non-binding agreements and their implications on its agenda. Even when an international understanding is formally non-binding, it may still generate legal consequences for the parties that endorse it.
Age of ‘treaty fatigue’
As described by a United Nations deputy secretary-general, the current era can be characterized as an age of “treaty fatigue.” Over the past two decades, states have increasingly moved away from rigid treaty-making processes and toward non-binding instruments such as memorandums of understanding. These arrangements allow governments to reach politically flexible agreements on sensitive issues without taking on strict legal obligations or navigating lengthy domestic ratification procedures.
The current US administration has largely embraced this approach. Donald Trump himself has generally spoken of “deals” rather than “treaties.”
Intent, not labels, determines legal character
Distinguishing a treaty, meaning a legally binding agreement, from a non-binding instrument has long been one of international law’s most persistent challenges. It is widely accepted that the title of a document is not decisive. What matters instead is the parties’ intention and their subsequent conduct.
The International Court of Justice has repeatedly affirmed this principle, including in its 2025 ruling in the Gabon-Equatorial Guinea dispute and earlier cases such as the Qatar-Bahrain maritime and territorial dispute. The court has emphasized that the determining factor is not form or terminology but the genuine “intention of the parties,” while recent jurisprudence has adopted a more restrictive approach.
The default assumption is that a document is not a treaty unless evidence demonstrates that the parties intended to create legal obligations.
Based on available evidence, official positions and published reports, the recent Iran-US understanding does not appear to reflect such legal intent and therefore is unlikely to qualify as a treaty. However, the parties’ future conduct could still shape both its legal nature and the scope of its effects. Planned signing ceremonies and official statements will be particularly important in this regard.
Challenge of durability in international documents
A longstanding assumption holds that turning an agreement into a treaty guarantees its durability and implementation. Experience suggests otherwise. Recent history, particularly Trump’s unilateral withdrawal from almost 70 to 80 international agreements, most of them formal and legally binding treaties, has shown that legal form alone offers little protection against the political choices of major powers. International law itself has often proved limited in addressing this reality.
State sovereignty encompasses freedom in treaty relations, and some scholars argue that withdrawal from treaties remains permissible unless explicitly prohibited. The history of international relations also shows that preserving and guaranteeing the implementation of agreements concluded with the United States is exceptionally difficult.
Even highly institutionalized bodies such as the World Trade Organization and the United Nations, both built upon strict legal frameworks, have struggled over time to develop effective enforcement mechanisms capable of restraining norm-defying US behavior.
The challenge is even more pronounced in Iran-US relations, which rest on deep distrust, a distrust further aggravated by the recent US aggression and crimes against the Iranian people. These realities cannot be ignored.
Rethinking concept of guarantees in international affairs
One objective reality must be acknowledged: in international relations, the notion of a guarantee, at least in the mechanical and absolute sense often invoked in domestic debates, simply does not exist.
In the absence of a supreme authority capable of enforcing international law, the most effective guarantee is the creation of reciprocal legal or political mechanisms built around the accepted principle of “self-help” in response to violations. The goal is to ensure that the cost of breaching commitments outweighs any potential benefit.
The challenge of securing compliance in agreements with the United States therefore cannot be addressed through legal instruments alone. Nor is this challenge unique to Iran. Countries around the world have faced it, as illustrated by US trade tariff policies over the past two years.
Calibrating expectations of international law
Curbing expectations about what international law can realistically achieve is essential for Iran’s foreign relations.
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