Outside powers have been trying to influence Iran for more than a century

A tenuous ceasefire remains in place between the United States and Iran. Yet, the two countries don’t seem to be close to a permanent peace deal. That has left policymakers and observers debating whether diplomacy can produce a stable settlement.

While that’s an open question, even reaching a deal would not exactly mark the end of the crisis. Rather, it would just be the latest chapter in a long struggle over sovereignty and foreign influence in Iran. Understanding this backstory helps explain why any settlement will be fragile, contested and shaped by deep mistrust on both sides.

Since the early 1900s, Iran has repeatedly sought to assert its sovereignty while also aiming to play an important role in regional affairs and international politics. That has brought Iranians into regular conflict with outside powers, who have repeatedly attempted to shape or constrain its role internationally. In other words, the confrontation that erupted in 2026 isn’t new. Instead, it reflects the unresolved tensions that have defined Iranian history for more than a century.

Iran entered the 20th century as a formally independent but politically fragile state. The Constitutional Revolution, which took place between 1905 and 1911, created Iran’s first parliament, and represented the earliest major attempt to strengthen the country internally and assert national sovereignty. At the time, Iran was ruled by a weak monarchy whose authority depended heavily on regional elites and foreign powers, leaving the central government unable to fully control its own territory.

This attempt at asserting national sovereignty ran headlong into geography: Iran’s location placed it at the center of imperial competition. In 1907, Britain and Russia divided the country into spheres of influence without Iranian participation, demonstrating how easily outside powers could limit Iranian autonomy. Foreign companies secured lucrative concessions that gave them control over key industries. The most notable was the Anglo — Persian Oil Company, later known as the Anglo — Iranian Oil Company, which dominated Iran’s oil production, often only providing limited benefits to the Iranian state and its people.

Foreign intervention intensified during World War I. Although Iran declared neutrality, Russian, British and Ottoman forces repeatedly crossed into its territory. The central government proved unable to enforce its sovereignty, and the conflict exposed the weakness of Iranian institutions. These experiences reinforced the sense among many Iranians that a stronger state was necessary if the country was to defend its independence.

That belief helped bring Reza Khan to power in 1921. As Reza Shah Pahlavi, he pursued an ambitious project of state building intended to strengthen Iran’s ability to act independently. The new Shah reorganized the army, expanded the bureaucracy and launched major infrastructure projects. These reforms sought not only modernization but also the consolidation of national authority in a region that had been dominated by the great powers.

Still, Pahlavi was unable to fully purge foreign influence from Iranian society. British companies continued to dominate Iran’s oil industry, reminding many Iranians that political sovereignty did not necessarily mean economic autonomy.

World War II again exposed Iran’s vulnerability. In 1941, British and Soviet forces invaded Iran to secure supply routes and eliminate perceived German influence. Reza Shah was forced to abdicate, and his 22-year-old son Mohammad Reza Pahlavi assumed the throne. The occupation also brought the United States into Iranian affairs. American personnel helped operate the Persian Corridor, the wartime supply route through which American aid reached the Soviet Union.

For many Iranians, the United States initially appeared distinct from older imperial powers. Britain remained associated with decades of concessions and interference, while the Soviet presence in northern Iran raised fears of territorial fragmentation.

By comparison, American diplomacy raised hopes that the United States might help safeguard Iranian sovereignty, rather than trampling on it. In 1945 and 1946, Soviet forces — which had been part of the World War II Allied occupation to secure supply routes and oil installations — refused to withdraw from northern Iran and supported separatist movements there. Washington backed Iranian efforts to secure the withdrawal of Soviet forces, reinforcing the perception that the United States could serve as a counterweight to foreign domination.

Yet, this moment also marked the beginning of deeper American involvement in Iran.

The decisive turning point came in the early 1950s, when another crisis arose over control of Iran’s vast oil resources. In 1951, Prime Minister Mohammad Mossadegh nationalized the Anglo — Iranian Oil Company, the British-controlled firm that dominated Iran’s oil industry. The decision was widely celebrated in Iran as an assertion of economic sovereignty.

Britain, however, responded with an embargo that crippled Iranian oil exports. Although the United States initially attempted mediation, and President Harry Truman resisted British plans to overthrow Mossadegh’s government, Cold War concerns soon reshaped the crisis. American officials feared that political instability in Iran could open the door to Soviet influence over one of the world’s most important oil-producing regions. In 1953, those concerns prompted President Dwight Eisenhower to green light a covert Anglo—American operation, which helped topple Mossadegh’s elected government and restore the authority of Mohammad Reza Shah.

For American policymakers, the coup stabilized a strategically important country. For many Iranians, however, it confirmed the belief that foreign powers continued to meddle in their affairs — with catastrophic consequences. The memory of 1953 became one of the most powerful symbols in modern Iranian political rhetoric.

In the decades that followed, Iran became one of Washington’s closest regional partners. Military cooperation expanded rapidly, oil revenues financed ambitious development programs, and Iran joined Western security arrangements designed to contain Soviet influence in the Middle East. The Shah’s White Revolution, a series of modernization reforms launched in the 1960s, attempted to transform the country through land reform, expanded education and industrial development. By the 1970s, Iran possessed one of the most powerful armed forces in the region and played a growing role in Middle Eastern politics.

Modernization also generated tensions. Rapid urbanization disrupted traditional social structures, economic growth remained uneven and political opposition was tightly controlled. The close relationship between the monarchy and the United States strengthened the perception that Iran’s political order depended partly on foreign support. The Shah’s security services suppressed political dissent, imprisoned opponents and used torture against suspected critics, reinforcing the belief among many Iranians that Washington supported an increasingly authoritarian regime with little regard for their suffering.

In 1979, these tensions exploded, fueling the Iranian Revolution. Ayatollah Ruhollah Khomeini led a movement that overthrew the monarchy and established the Islamic Republic. The new regime defined itself in opposition to the system of foreign influence that many Iranians believed had shaped their country for decades. The seizure of the American embassy in Tehran later that year transformed hostility into open confrontation.

Subsequent events hardened this divide. In the 1980s, the Iran — Iraq War reinforced the revolutionary leadership’s belief that Iran faced constant external threats, while American support for Iraq deepened mistrust in Tehran. In the decades that followed, sanctions, regional rivalries and disputes over Iran’s nuclear program became central to the relationship. The nuclear agreement of 2015 briefly reduced tensions, but its collapse in 2018 restored sanctions and revived confrontation.

Western sanctions, financial restrictions and diplomatic pressure disrupted everyday life by driving up prices, limiting access to medicine and constraining economic opportunity for ordinary families. Even Iranians who opposed their own government often came to resent the United States and its allies, believing that outside pressure was punishing the population as much as the regime.

American allies, particularly Israel, played central roles in escalating tensions with Iran, which intensified over the course of more than three decades through repeated strikes, reprisals and sustained external pressure on the Islamic Republic. By the mid-2020s, the boundary between limited escalation and open war had become increasingly fragile. These dynamics reinforced the broader pattern traced throughout Iran’s modern history: outside powers continued to seek ways to constrain Iran’s regional role, while Iran viewed such pressure as another challenge to its sovereignty.

This history makes clear that any peace agreement reached in 2026 will not necessarily represent a final resolution but another stage in a long struggle over Iran’s sovereignty and its role in the regional order. For more than a century, Iran has attempted to assert both independence and influence, while outside powers have repeatedly tried to shape the country’s place in the Middle East.

Whether diplomacy eventually succeeds or fighting resumes, the central challenge will remain the same: building a settlement that addresses the deeper sources of mistrust between Iran and outside powers. At the heart of that mistrust lies the long history of foreign intervention in Iranian affairs and Iran’s repeated efforts to defend its sovereignty. Any durable agreement will therefore require not only credible security arrangements addressing concerns about Iran’s nuclear program, but also recognition of sovereignty and clear limits on foreign interference. Without confronting these historical realities, any agreement is likely to prove temporary.

Zach Battat is a historian specializing in the modern Middle East.

Made by History takes readers beyond the headlines with articles written and edited by professional historians. Opinions expressed do not necessarily reflect the views of the Inquirer.