By September 2025, efforts to revive the 2015 Iran nuclear deal remain deadlocked. Dispute centers on Iran’s ballistic missile program, which the U.S. demands be included. Tehran strongly rejects this. Ali Larijani, Iran’s Security Council Secretary, posted that linking missiles to nuclear talks makes negotiations inaccessible but leaves options open.
Discussions already undermined by years of mistrust collapsed during the sixth round of indirect negotiation in June 2025, mediated by Oman. The talks were called off after 12 days of intense exchange that involved Israeli bombing of Iranian targets and Iranian retaliation with missiles, making diplomatic momentum even more difficult. The demand by Washington since then that Iran should accept constraints on the development of missiles has now become a red line not to be crossed by either side, further complicating the stalemate.
Iran’s Position On Sovereignty And Defense
Iran is adamant that its missile program is a national issue of national defense and cannot be negotiated internationally. Authorities in Tehran believe that nuclear diplomacy should not be based on conventional deterrence measures such as missiles, but on uranium enrichment and civil nuclear activities. Larijani and other political leaders emphasize that the two problems should not be tied together either diplomatically or strategically.
Recent developments in Iran which have seen its uranium being enriched to 60 percent purity, a step closer to weapons grade uranium, further embolden its position. The Iranian authorities are claiming that these developments are legal in the framework of the NPT unless weaponization is achieved, but international observers are worried about the reduction in the time-scale of breakout. Threats by Iranian hardliners to withdraw the Non-Proliferation Treaty and expel IAEA inspectors due to potential sanctions by the UN are indications of increased pressure on the leaders to stand on their feet rather than to compromise.
Resistance To Expanding Nuclear Talks Scope
The Iranian government is still unwilling to be part of a future deal, but this time they insist that they will only be part of a deal that will be mutually respected and that they will not make any commitments that they will not keep. Iranian leaders cite the US backing out of the Joint Comprehensive Plan of Action (2015) (JCPOA) in 2018 as a betrayal that weakens the existing compliance expectations. Having this in mind, they oppose the introduction of missile restriction as an excess that changes the terms of previous accords.
US And European Diplomatic Pressure
In the case of Washington, any plausible avenue of reviving the JCPOA would now need to incorporate the missile capability of Iran. US Special Envoy, Steve Witkoff has identified that a nuclear deal cannot secure long-term regional and global security without verifiable limitations on missile building. The Biden administration was at one point thinking of decoupling the two matters, but continued pressure by Congress and regional partners, most notably Israel and the Gulf State, has made it adopt a more aggressive approach.
The team led by Witkoff has also pointed out that in the event of failure of diplomacy, the US will seek other means such as reinstating sanctions, diplomatic isolation by the UN and perhaps military rivals acting in coordinated action. The new US strategy is driven by historical experience, especially the shortcomings of the original JCPOA to prevent the parallel development of the Iranian missile program in the 2015-2018 period.
European Support For Renewed Pressure
French, German, and United Kingdom signatories of the JCPOA-have invoked the dispute resolution mechanism in the JCPOA, the so-called snapback, because of Iran’s non-compliance with nuclear inspection access and uranium-stockpile restrictions. Such countries have also demanded Tehran to resume negotiations before a one-month deadline to comply lapses in October 2025.
The restraint demanded of Europe is to some extent compensated by the fear of retaliation by Iran that would also imply intervention in oil markets and destabilization of conflicts in the region. However, it is agreed between the transatlantic allies that Iran should resume full compliance and permit IAEA inspectors to access it freely in case of a renewal of diplomatic initiatives.
Economic And Regional Ramifications
The long period of diplomatic freeze still puts a strain on the Iranian economy. The Rial has hit new lows against the dollar and inflation is skyrocketing and imports of foods are declining due to increased sanctions. These circumstances have resulted in occasional demonstrations in big cities but the government has been able to quell these demonstrations by employing more internal security measures.
Tehran sees its survival even during the economic crisis as a strategy of endurance. The fact that Iran is able to resist pressure is described by nationalist media as what is strong about the Islamic Republic, and the Western sanctions are portrayed as neither just nor effective. Authorities are trying to trade with China and Russia to eliminate isolation, but with little success in counterbalancing domestic economic suffering.
Tensions With Regional Adversaries
There is the fact that mounting instability in the regional environment is being piled on top of an increased instability through the nuclear standoff. Israel has continued to speak loudly against any agreement that does not include missile limitations and has intensified its covert activities against Iranian officials and installations. Meanwhile, missile action in the Levant, particularly in Syria, Iraq and Lebanon–has been increasing, proxies on both sides pushing boundaries.
The war raging in Yemen, which has been strengthened by Iranian alliances with the Houthis, is a flammable hinge and so are the activities of Shiite militias in Iraq. Such conflicts are also increasingly being considered not just as regional conflicts but as a continuation of the Iran-US geopolitical confrontation. The failure of every negotiation makes the solution of these peripheral yet interconnected crises even more complicated.
The Diplomatic Crossroads
With the tension building, the possibility of new discussions exists but is weak. Backchannels between the two have remained open through the mediators in Oman and Qatar. Policy circles have acknowledged that, in spite of entrenched views, the price of complete diplomatic breakdown can be higher than the compromises needed to get ahead.
Some of the leading personalities such as Ali Larijani have indicated that diplomacy has not died yet. In a more recent statement to the masses, Larijani admitted that the road to negotiations is not shut but said that the Iranian missile program could under no circumstances be surrendered or traded.
The path for negotiations with the US is not closed; yet these are the Americans who only pay lip service to talks and do not come to the table; and they wrongfully blame Iran for it.
— Ali Larijani | علی لاریجانی (@alilarijani_ir) September 2, 2025
WE INDEED PURSUE RATIONAL NEGOTIATIONS. By raising unrealizable issues such as missile…
This puts the Iranian position into focus: diplomacy can be revived, however, within the confines that would protect both national pride and national strategic autonomy.
The Role Of External Powers
Russia and China continue to back Iranian demands against unilateral sanctions and to favour diplomatic flexibility. Moscow has employed its veto power in the Security Council to frustrate the efforts of the Western led sphere, whereas, Beijing focuses on economic interaction via the Belt and Road Initiative. Their support makes the efforts by the West to isolate Iran, establish a diplomatic multipolarity and weaken the bargaining power of the US difficult.
At the same time, Gulf states such as Saudi Arabia and the UAE have cautiously welcomed tougher pressure on Iran, while also pursuing hedging strategies through limited normalization efforts. This regional balancing act reveals that Iran’s nuclear diplomacy reverberates far beyond the immediate actors, shaping alignments and rivalries throughout the Middle East and beyond.
Strategic Uncertainty And The Future Of Nonproliferation
The impasse between Iran and the United States in 2025 highlights a deeper tension within nonproliferation diplomacy: the challenge of aligning national sovereignty with global security norms. While the world remains focused on preventing nuclear weaponization, the tools available to enforce compliance are increasingly constrained by geopolitical fragmentation and eroded trust.
The missile issue is not simply a technical matter of arms control, but a symbol of broader strategic divergence. The United States views comprehensive disarmament as essential for regional stability, while Iran views missile development as an indispensable component of deterrence, especially under persistent threat.
Whether this impasse will evolve into renewed talks or escalate into broader confrontation remains uncertain. What is clear, however, is that the window for constructive diplomacy is narrowing. The next few months will test whether mutual interests can overcome entrenched positions or whether the Middle East is headed for a deeper phase of strategic fragmentation.
