Trump warns Iran deal ‘not final’ ahead of formal signing on Friday

In 2017, then-US President Donald Trump issued a stark warning that the Iran nuclear deal, formally known as the Joint Comprehensive Plan of Action (JCPOA), was “not final” and threatened renewed military action. This article examines the legal implications of such a pronouncement on a multilateral international agreement, particularly in light of the US's subsequent withdrawal from the JCPOA in 2018. It delves into the principles of international treaty law, including *pacta sunt servanda* as enshrined in the Vienna Convention on the Law of Treaties, and contrasts the unilateral US action with the structured approach to treaty-making observed by states like Kenya. The analysis extends to the current landscape, noting ongoing efforts in June 2026 to forge new agreements between the US and Iran, underscoring the enduring relevance of international legal frameworks despite past challenges.

In a statement that sent ripples through the international community in 2017, then-US President Donald Trump declared that the Iran nuclear deal, the Joint Comprehensive Plan of Action (JCPOA), was “not final” and warned of potential military repercussions if Iran did not "behave." This pronouncement, made ahead of the deal's formal signing, signaled a significant departure from established diplomatic norms and raised profound questions about the sanctity of international agreements. The excerpt from KBC Kenya highlights the immediate concern surrounding such a unilateral declaration regarding a painstakingly negotiated multilateral accord.

This article aims to provide a comprehensive legal analysis of the implications arising from President Trump's stance on the JCPOA. It will explore the foundational principles of international law governing treaties, the specific legal status of the JCPOA, and the ramifications of a major power's unilateral withdrawal. For legal practitioners in Kenya and across Africa, understanding these dynamics is crucial, as the stability of the international legal order directly impacts global trade, security, and diplomatic relations, influencing how states engage with and rely upon international commitments.

The analysis will trace the evolution from President Trump's initial warning in 2017 to the US's formal withdrawal from the JCPOA in 2018, and further contextualize these events against the backdrop of current (June 2026) diplomatic efforts to establish new frameworks between the US and Iran. By examining these developments through the lens of international law, particularly the Vienna Convention on the Law of Treaties, this article seeks to illuminate the challenges posed to the principle of *pacta sunt servanda* and the broader implications for the enforceability and reliability of international agreements.

The Joint Comprehensive Plan of Action (JCPOA), commonly known as the Iran nuclear deal, was a landmark agreement finalized in Vienna on July 14, 2015. It was the culmination of thirteen years of negotiations between Iran and the P5+1 group—comprising the five permanent members of the United Nations Security Council (China, France, Russia, the United Kingdom, and the United States) plus Germany—along with the European Union. The primary objective of the JCPOA was to significantly constrain Iran's nuclear program, ensuring its peaceful nature, in exchange for the lifting of nuclear-related international sanctions.

The legal status of the JCPOA, while sometimes debated, was widely considered a binding international legal framework, particularly given its endorsement by United Nations Security Council Resolution 2231 on July 20, 2015. This resolution made the agreement an integral part of international law, obliging all UN member states to respect its provisions. The framework for understanding such international agreements is largely provided by the Vienna Convention on the Law of Treaties (VCLT) of 1969, which codifies customary international law regarding treaties between states. A cornerstone principle of the VCLT, and indeed of international law, is *pacta sunt servanda*, meaning 'agreements must be kept'. This principle underscores the expectation that states will honor their treaty obligations in good faith, providing stability and predictability in international relations.

President Trump's 2017 warning that the JCPOA was "not final" and his subsequent unilateral withdrawal on May 8, 2018, presented a significant challenge to established international legal norms. The VCLT provides specific grounds and procedures for the termination of or withdrawal from a treaty, including in conformity with the treaty's provisions, by consent of all parties, or in exceptional circumstances such as a material breach or a fundamental change of circumstances, typically requiring a 12-month notice. The US withdrawal from the JCPOA did not align with these provisions, as the agreement itself did not contain a unilateral withdrawal clause for the reasons cited by the Trump administration, nor was there a consensus among the other parties.

Indeed, in response to the US withdrawal, the leaders of France, Germany, and the United Kingdom issued a joint statement affirming that the UN Security Council Resolution endorsing the nuclear deal remained a "binding international legal framework." This highlights a fundamental tension: while a state may assert its sovereign right to withdraw from an agreement, such actions, especially when unilateral and not in accordance with established international law, can undermine the credibility of multilateral diplomacy and raise questions about the reliability of international commitments. The principle of *pacta sunt servanda* is crucial for maintaining order in the international system, and its erosion can lead to increased uncertainty and instability.

Following the US withdrawal, Iran began to disregard some of the limitations on its nuclear program, leading to a deterioration of the original deal. However, the international community's engagement with Iran has continued to evolve. As of June 2026, there are significant new developments: the US and Iran have reportedly reached a framework agreement or Memorandum of Understanding (MOU), slated for signing on June 19, 2026, aimed at ending a conflict and reopening the Strait of Hormuz. This new agreement reportedly includes provisions for future technical negotiations on Iran's nuclear program and potential sanctions relief, indicating a renewed, albeit complex, diplomatic effort. This ongoing negotiation underscores the persistent need for international agreements to manage complex geopolitical issues, even after previous accords have been challenged.

From a Kenyan legal perspective, the country's commitment to structured international engagement is evident in its domestic legal framework. The Treaty Making and Ratification Act, 2012, governs the process by which Kenya enters into and implements international treaties. This Act mandates parliamentary oversight and public participation in the treaty-making process, ensuring that Kenya's international obligations are consistent with its constitutional values and national interests. This structured approach contrasts sharply with the unilateralism demonstrated by the US withdrawal from the JCPOA, emphasizing Kenya's adherence to a rule-based international order.

The episode surrounding the Joint Comprehensive Plan of Action, from President Trump's initial warning to the US withdrawal and the subsequent efforts to forge new agreements, serves as a critical case study in the complexities and fragilities of international law. It underscores the paramount importance of the principle of *pacta sunt servanda* and the structured mechanisms for treaty termination or withdrawal as outlined in instruments like the Vienna Convention on the Law of Treaties. Unilateral actions, while reflecting sovereign prerogatives, inevitably introduce uncertainty and can erode the foundational trust necessary for effective multilateral diplomacy.

For legal practitioners in Kenya, these developments highlight the dynamic and often unpredictable nature of international relations and their impact on legal frameworks. Advising clients on international trade, investment, and compliance requires a keen awareness of both established international legal principles and the geopolitical realities that can challenge them. The ongoing efforts to negotiate new agreements between the US and Iran, even after the significant disruption to the JCPOA, demonstrate the enduring necessity of diplomatic engagement and the continuous evolution of international legal instruments. Practitioners must remain vigilant, understanding that while international law provides a framework for order, its application can be subject to political will and strategic shifts, necessitating adaptable and informed legal counsel.