Iran–US Relations: Background Briefing
Overview
Iran–US relations are defined by decades of hostility, limited diplomacy, and recurring crises over Iran’s nuclear program, regional security, sanctions, and detentions. The two countries have not had formal diplomatic relations since 1980, following the 1979 Iranian Revolution and the seizure of the US Embassy in Tehran. Since then, contacts have been managed indirectly—often through intermediaries such as Oman, European governments, or multilateral forums.
Today, the relationship is shaped by several overlapping issues: Iran’s advancing nuclear activities, US sanctions pressure, conflicts involving Iran-backed armed groups across the Middle East, maritime security in the Gulf, prisoner exchanges, and the risk of direct military escalation. Although both sides periodically signal openness to limited de-escalation, mutual distrust remains deep.
Historical context
The modern relationship is heavily influenced by two formative events. First, the 1953 coup in Iran, backed by the United States and the United Kingdom, helped restore Shah Mohammad Reza Pahlavi and left a lasting legacy of Iranian suspicion toward Washington. Second, the 1979 Islamic Revolution overthrew the shah and brought to power a regime explicitly opposed to US influence. Later that year, Iranian students seized the US Embassy and held American diplomats hostage for 444 days.
The US severed diplomatic relations with Iran in 1980. During the 1980s, tensions widened during the Iran-Iraq War, including US naval clashes with Iran in the Persian Gulf. In the decades that followed, Washington increasingly viewed Iran as a state sponsor of terrorism and a destabilizing regional actor, while Tehran cast the US as a hostile power seeking regime change.
The nuclear issue
The nuclear file has been the central issue in relations for the past two decades. Concerns about Iran’s nuclear program intensified in the early 2000s after previously undeclared nuclear facilities came to light. Iran maintains that its program is peaceful and for civilian purposes; the US and its partners have long feared that Tehran seeks at least the option to build a nuclear weapon.
These tensions led to multilateral diplomacy between Iran and the five permanent members of the UN Security Council plus Germany. In 2015, the parties concluded the Joint Comprehensive Plan of Action (JCPOA). Under the deal, Iran accepted strict limits on uranium enrichment, stockpiles, and nuclear infrastructure, along with enhanced international monitoring, in exchange for sanctions relief.
The agreement marked the most important diplomatic breakthrough in modern Iran–US relations. However, it was also politically contested in both countries. In 2018, the Trump administration withdrew the United States from the JCPOA and reimposed broad sanctions under a “maximum pressure” campaign. Iran initially remained within the deal’s limits but later reduced compliance step by step, expanding enrichment and limiting some monitoring access.
Efforts under the Biden administration to restore the JCPOA did not produce a full return to the agreement. As a result, the nuclear issue remains unresolved, with Iran possessing a far more advanced nuclear program than it did under the original deal framework. This has increased concerns in Washington, Israel, and Europe about breakout timelines and the risk of military confrontation.
Sanctions and economic pressure
US sanctions are one of Washington’s main tools against Iran. They target Iran’s banking system, energy exports, shipping, military procurement, and individuals and entities tied to the Islamic Revolutionary Guard Corps (IRGC), missile development, human rights abuses, or regional proxy networks.
These sanctions have imposed major costs on Iran’s economy, including reduced oil revenue, currency pressure, inflation, and constrained access to global finance. The US says sanctions are intended to pressure Iran to change its behavior on the nuclear program, missiles, and regional activities. Iranian officials argue that the sanctions amount to economic warfare and disproportionately harm civilians.
Sanctions policy is also tied to diplomacy: access to frozen funds, oil export waivers, and enforcement intensity have at times been adjusted in connection with negotiations or humanitarian arrangements.
Regional conflict and security
Iran–US tensions are inseparable from wider Middle East dynamics. The US maintains military forces and partnerships across the Gulf, Iraq, Syria, and elsewhere. Iran has built influence through allied governments, militias, and armed groups in Iraq, Syria, Lebanon, Yemen, and the Palestinian territories. Washington sees these networks as destabilizing; Tehran presents them as part of a deterrence strategy and “axis of resistance.”
This has led to repeated flashpoints. In Iraq and Syria, Iran-backed militias have targeted US personnel and bases, while the US has carried out retaliatory strikes. Maritime incidents in the Gulf and attacks on oil infrastructure have also raised fears of escalation.
A major turning point came in January 2020, when the United States killed IRGC Quds Force commander Qassem Soleimani in Baghdad. Iran responded with missile strikes on US forces in Iraq. Although both sides stopped short of full-scale war, the episode showed how quickly tensions can escalate.
The war in Gaza since October 2023 has intensified regional risks. Iran supports groups hostile to Israel and the US, while Washington has sought to deter broader escalation and protect its forces and partners. Attacks by Iran-aligned groups on US troops, Red Sea shipping, and Israeli targets have sharpened the possibility of direct or indirect confrontation.
Diplomacy, intermediaries, and detainees
Despite hostility, diplomacy has never fully stopped. Because the two countries lack embassies, communication is often indirect. Oman, Qatar, Switzerland, and European states have frequently acted as channels for messages or negotiations. The International Atomic Energy Agency (IAEA) also plays a central role on the nuclear file by monitoring Iran’s nuclear activities.
One area where limited progress has occasionally been possible is detainee diplomacy. Iran has detained US citizens and dual nationals, often on espionage or national security charges that Washington calls baseless. Prisoner swaps and arrangements involving access to restricted Iranian funds have periodically eased tensions, though they have not changed the overall trajectory of the relationship.
Key actors
In Iran: Supreme Leader Ayatollah Ali Khamenei has ultimate authority on major strategic decisions, including relations with the US. The president and foreign ministry manage day-to-day diplomacy, but the IRGC is central on regional security and deterrence. Iran’s political system contains competing factions, though skepticism toward Washington is widespread across the establishment.
In the United States: The president sets overall Iran policy, supported by the State Department, Pentagon, intelligence community, and Treasury Department, which administers sanctions. Congress also shapes policy through legislation, oversight, and political pressure. US allies—especially Israel and Gulf Arab states—have significant influence on Washington’s approach.
International actors: European powers, Russia, China, Gulf states, and Israel all affect the bilateral relationship. Europe has generally supported diplomacy tied to nuclear constraints. Israel strongly opposes any outcome it sees as leaving Iran too close to nuclear weapons capability. China and Russia maintain ties with Iran and can help blunt its isolation.
Current state of affairs
Iran–US relations remain adversarial, transactional, and highly volatile. Neither side appears close to a broad normalization. The main near-term goals are more limited: avoiding war, containing regional escalation, managing the nuclear risk, and preserving channels for crisis communication.
The central dilemma is that both sides want deterrence without uncontrolled escalation. The US seeks to constrain Iran’s nuclear advances and regional activities while protecting troops and allies. Iran wants sanctions relief, security, and recognition of its regional role, while resisting pressure that it sees as coercive. With no durable diplomatic framework in place, the relationship is likely to remain vulnerable to sudden shocks.