What weeks of military confrontation could not accomplish seemed briefly possible on June 17 when the United States and Iran signed a memorandum of understanding. It lengthened the truce, opened a path back to negotiations and raised hopes of restoring stability to one of the world’s most strategically important regions.
At first things looked good. Commercial shipping through the Strait of Hormuz, which carries about a fifth of the world’s oil trade, began to recover. Oil flows rose and Iranian exports more than doubled from wartime lows under a temporary sanctions waiver. The week of June 22-28 was the busiest since hostilities began on Feb. 28, with about 340 commercial vessels passing through the Strait. For a moment it appeared that diplomacy was working.
Within weeks ships were disappearing again from the strait. Military exchanges resumed and soon mediators were calling for another temporary truce just to save the original deal. What seemed like a breakthrough had become another fragile ceasefire. Its collapse revealed a flaw in the mediation: the parties had agreed on a political text, but not on the mechanisms to make it work, and the states that brokered the deal lacked the leverage to make them do so.
Not implementation, signatures

Part of the problem was that the signing of the agreement became the end rather than the beginning. The U.S. and mediators worked on drafting a political text both sides could live with. They measured success by signatures and public declarations, not paying enough attention to what actually happens when governments, militaries, regulators, banks, insurers, shipping companies and regional allies try to implement an agreement. Questions about interpretation, sequencing, verification, dispute resolution and confidence-building were deferred rather than resolved.
The June MoU, like many cease-fire arrangements, was based on constructive ambiguity. Then it all made sense. Both Washington and Tehran needed sufficient political wiggle room to sell the deal to domestic audiences as a win while leaving hard issues unresolved. Ambiguity can move diplomacy forward when a complete agreement isn’t possible.
Ambiguity only works if there are clear mechanisms to deal with the ambiguity. Without it, divergences simply move from the negotiating table to the implementation stage, where trust is less and the political cost of failure is greater. The MoU was about keeping a nuclear “status quo,” not defining what activities were or were not permitted. It offered to ease sanctions but did not say which restrictions would be lifted, by what legal authority or on what timeline. It pointed to frozen Iranian assets but gave no details on how the funds would be released, controlled or monitored. Roughly $12 billion was reportedly on the table, yet disputes quickly surfaced over whether that money would sit in supervised escrow accounts or move under unrestricted Iranian control.
A Strait Without Rulebook
The maritime provisions were equally defective. The deal required Iran to “make arrangements using its best efforts for the safe passage of commercial vessels” and to discuss with Oman the future administration and maritime services of the Strait of Hormuz “in accordance with applicable international law and the sovereign rights of the coastal states.But it did not create a common framework for navigation, maritime security, inspection procedures, routing, or dispute resolution. The wording left room for Tehran to interpret the accord as recognizing a future Iranian role in the management of the strait.
There was an initial recovery in commercial traffic as markets reacted to news of the ceasefire. But confidence remained fragile, because the institutional arrangements needed to sustain normal shipping had never been agreed. Washington said it would temporarily waive sanctions for 60 days for limited sales of oil, banking, insurance and shipping. But many insurers, refiners and shipping firms remained cautious anyway. The two-month legal window was not enough to justify the resumption of billions of dollars in commercial relations.
The respite, while it lasted, was a boon to Iran. The waiver period is estimated to have exported some 70 million barrels of oil, worth roughly $5 billion to $6 billion. But oil shipped to tankers does not turn immediately into unrestricted cash in Tehran’s hands. Sanctions, escrow arrangements and banking procedures were not clear, and commercial recovery did not bring the economic relief the agreement was meant to provide.
The ceasefire also gave both sides time to prepare for the possibility of diplomacy failing. The U.S. increased its military stockpiles and moved assets around the region. Iran used the pause to engineer a political transition and project continuity through the funeral of the supreme leader. Mediators had hoped that time would bring political progress. Instead, both governments used it to strengthen their own position in case negotiations failed. That is the key lesson: implementation is not an administrative afterthought to successful diplomacy. It’s diplomacy, but done differently. If an agreement is to stick, continued mediation is needed for every disagreement about sequencing, sanctions, verification, compliance or interpretation.
More mediators, same leverage problem
The shortcomings of the MoU’s implementation were not simply a matter of poor drafting. This was symptomatic of a broader problem with the mediation process itself: the states that brokered the agreement had enough trust to bring the parties together, but not enough leverage to compel them to resolve disputes or follow through on commitments once implementation began.
One good thing is that the mediatory effort has expanded. What began as a predominantly Pakistani endeavor has evolved into a wider diplomatic coalition with Qatar, Egypt and other regional partners now backing efforts to restore the ceasefire and get talks back on track. The expansion spreads the political, financial and logistical burden of mediation, gives access to more regional stakeholders, including Israel and Hezbollah, and makes the process more resilient if any one channel gets blocked.
But growth alone will not solve the underlying problem. New mediators are trusted interlocutors, with close regional ties like the original mediators, but limited leverage over the strategic calculations of Washington and Tehran. They can help encourage dialogue, diffuse misunderstandings and keep negotiations on track. They aren’t able to implement it themselves.
The latest proposals highlight the point. Mediators are discussing opening a southern route backed by the U.S. that was hit by Iranian attacks, and a “Iran-approved” northern shipping route that is now affected by the U.S. naval blockade. “They are also looking at options for transit fees, such as a jointly run fund or a system that would allow Iran to collect fees related to maritime security and environmental services.” Such ideas might help revive the MoU but are unlikely by themselves to secure a durable ceasefire, restore confidence in commercial shipping or sustain meaningful sanctions relief.
What would a durable implementation require
Sustainable implementation requires a different kind of international support. “Stronger external guarantors will become more important as the negotiations move from agreeing principles to enforcing obligations. Major powers with genuine economic, political and strategic weight can provide inducements, reassurance and, when appropriate, pressure that smaller mediating states cannot generate on their own. They will not be replacing the current mediators, who are vital for their credibility and relationships in the region. It would be a complement to that work in providing the leverage that is necessary to sustain implementation and assure both sides that commitments will in fact be honored.
The next phase of diplomacy isn’t just about enlarging the circle of mediators. It’s about diversifying who is in that circle. Washington and Tehran could be brought together by trusted regional mediators. But without guarantors able to ensure implementation and impose real costs for non-compliance, any new agreement is in danger of meeting the same fate as the June MoU: signed with optimism, briefly observed and quickly undone.













