U.S.–Iran Nuclear Talks: Narrow Scope Meets Expanding Security Demands

Diplomacy between Washington and Tehran has once again settled into a familiar pattern: negotiations proceed, but expectations diverge. At the center of the impasse lies a structural disagreement about scope. Iran insists that talks remain confined to its nuclear program. The United States, backed by regional allies, argues that any durable agreement must also address ballistic missile development and Tehran’s network of regional proxies.

The result is a negotiation defined less by technical nuclear parameters than by competing strategic visions.

Iran’s Narrow Negotiating Mandate

For Iran, the nuclear file is a discrete issue capable of transactional resolution. Tehran has signaled at various points that it could contemplate measures such as shipping out enriched uranium under certain conditions. But Iranian officials have consistently resisted expanding the agenda beyond the nuclear program. As Ibrahim Al-Assil, Senior Research Fellow at Harvard’s Middle East Initiative at the Belfer Center, explains, “The Iranians… don’t want to negotiate on anything beyond the nuclear file.” He adds that even within the nuclear portfolio, “they have their own constraints.”

Those constraints are not purely technical. They are political and ideological, shaped by domestic pressures and long-standing suspicions of Western intentions. For Tehran, broadening talks risks transforming a manageable arms-control negotiation into a debate over the very architecture of its regional strategy.

Washington’s Expanding Security Agenda

Washington views the equation differently. Critics of the original 2015 nuclear agreement have long argued that isolating uranium enrichment from missile capabilities and regional militia networks produced a partial solution at best. Al-Assil notes that in the U.S., the earlier deal was criticized because “it didn’t address other security risks coming out from Iran,” specifically ballistic missiles and proxy militias. That critique has only grown louder amid continuing tensions across the Middle East.

The disagreement over scope reflects more than negotiating tactics; it reflects opposing theories of stability. Tehran appears to treat its nuclear program as separable from its broader security doctrine. The United States sees the nuclear program as one component of a wider strategy of deterrence, coercion and influence that spans Lebanon, Syria, Iraq, Yemen and beyond.

Regional Power Shifts and Strategic Calculations

The diplomatic challenge is further complicated by the evolving balance of power in the region. Iran’s proxy network, once seen as a decisive lever of influence, has been weakened in recent years by sustained military pressure and political shifts. Yet weakness does not necessarily translate into flexibility. Regimes under strain often double down rather than compromise. The question confronting policymakers is whether pressure narrows Tehran’s options toward agreement—or hardens its resistance.

Meanwhile, the United States faces its own strategic constraints. Sanctions and export controls have already reached a near-comprehensive level with respect to Iran. Any expansion of leverage would likely target secondary actors and third-country facilitators rather than Tehran directly. But economic pressure, however intense, does not automatically yield political concessions.

Jason Wright, a Partner at Steptoe LLP in New York who practices in the national security sector and served more than 20 years in the U.S. Army, frames the dilemma bluntly: “How do you negotiate with a regime that has nothing left to lose?” The question captures central uncertainty surrounding the talks. If Iran perceives its strategic position as existentially threatened—by domestic unrest, regional setbacks or escalating sanctions—its, its appetite for compromise may diminish rather than expand.

Deterrence, Missiles, and Proxy Networks

The broader regional context also weighs heavily on the diplomatic calculus. Missile development and proxy networks are not peripheral issues; they are embedded in Iran’s deterrence posture. From Tehran’s perspective, ballistic missiles offset conventional military asymmetries. Proxy alliances provide depth and deniability. For Washington and its partners, however, those same instruments represent destabilizing force multipliers that cannot be cordoned off from nuclear risk.

This divergence produces a negotiation geometry that is inherently unstable. A narrow nuclear deal may be achievable in technical terms—caps on enrichment levels, monitoring mechanisms, stockpile limits. Yet such an agreement could leave untouched the underlying security competition that fuels mistrust. Conversely, an effort to fold missiles and militias into the framework risks overloading the talks beyond what either side is prepared to concede.

The Diplomatic Path Forward

Time adds another layer of pressure. The longer negotiations stall, the more entrenched positions become. Domestic political cycles in both countries constrain flexibility. Regional actors, particularly Israel and Gulf states, shape Washington’s risk tolerance and strategic demands. Each passing month recalibrates the incentives for escalation versus compromise.

Diplomacy in this environment becomes less about drafting clauses and more about sequencing leverage. Policymakers must decide whether to pursue an incremental approach—securing nuclear constraints first and addressing other concerns later—or to insist on a comprehensive package from the outset. Both paths carry risks. The former may entrench unresolved disputes; the latter may produce no agreement at all.

Ultimately, the dispute over scope is a proxy for a deeper question: what kind of equilibrium is acceptable in the Middle East? If the objective is purely to prevent nuclear weaponization, a narrow deal could suffice. If the objective is broader regional stabilization, then missiles, militias and maritime security inevitably enter the frame.

The current moment suggests that neither side is ready to abandon its preferred theory of stability. Tehran seeks a focused nuclear bargain. Washington seeks structural change. Until those strategic visions converge—or until one side recalculates its tolerance for risk—the talks are likely to remain suspended between technical feasibility and political impossibility.