Tensions between the United States and Iran continue to complicate efforts to reach a lasting diplomatic agreement, with mutual distrust emerging as the primary hurdle. The two countries remain divided on key issues such as nuclear technology and security in the Strait of Hormuz, while historical grievances have deepened skepticism on both sides.

Iranian officials remain wary of the U.S. due in large part to actions taken during the Trump administration, notably the unilateral withdrawal from the 2015 Joint Comprehensive Plan of Action (JCPOA), better known as the Iran nuclear deal. After nearly two years of negotiations involving multiple world powers, the Trump administration abandoned the agreement without accusing Iran of violations, citing instead a broad dissatisfaction with the deal. This move was followed by renewed U.S. sanctions and military actions that further strained relations.

Iran’s leadership has since demanded guarantees that a future U.S. administration would not similarly abandon any new deal, but the Biden administration and its predecessors have maintained that such assurances cannot be provided. The legacy of mistrust is compounded by incidents during the Trump presidency, including targeted airstrikes on Iranian figures during early stages of diplomatic talks. Iranian officials view these actions as evidence that the U.S. could betray negotiations at any time.

Diplomatic efforts have faced setbacks recently, with a first round of talks ending on a sour note, partly due to Iranian concerns over U.S. intentions. Vice President JD Vance postponed a planned delegation trip to Pakistan for further discussions after Iran raised such trust issues again. Masoud Pezeshkian, Iran’s president, warned in a phone call with Pakistan’s prime minister that the U.S. may repeat past patterns of undermining diplomacy.

Experts note that Iran is likely to insist on incremental and verifiable steps that preserve some leverage, such as maintaining partial control over its uranium stockpile during negotiations. However, any meaningful agreement would require Iran to make irreversible concessions, including surrendering uranium supplies enriched beyond peaceful levels. On the U.S. side, promised concessions, like easing sanctions or unlocking frozen assets, are seen as reversible and less concrete.

This imbalance has contributed to a cautious approach from Iran, as it tests U.S. compliance through gradual implementation. Veteran diplomats warn that such a step-by-step process stands in contrast to the Trump administration’s often impatient stance, which could hinder progress.

Underlying the impasse is Iran’s enduring suspicion of U.S. motives, amplified by the close military and political alignment between Washington and Israel. Israeli Prime Minister Benjamin Netanyahu’s push to renew joint U.S.-Israeli military actions against Iran after a cease-fire expires has heightened Iranian fears that diplomacy might be undercut by force.

U.S. officials counter that Iran’s record of concealing military nuclear activities and violating international commitments justifies caution and skepticism toward Iran’s assurances. Former administration officials point to Iran’s history of secret nuclear sites and misleading the International Atomic Energy Agency as grounds for distrust.

Despite these deep-seated divisions, both sides continue to express a willingness to engage in diplomacy. Reaching a comprehensive deal would likely take months or even years, reflecting the complexity of balancing security concerns, verification mechanisms, and political realities.

Observers emphasize that overcoming decades of hostility and repeated diplomatic failures will require patience and rigid verification measures. Whether the United States and Iran can rebuild trust to a level sufficient for a durable agreement remains uncertain but is critical to stabilizing a volatile region.