“Making peace with Iran may be just as painful as winning the war,” a recent CNN report observed. As negotiations proceed amid a fragile ceasefire, the contours of a potential US-Iran agreement—and its durability—remain uncertain.
As a scholar of ancient Persia, the antecedent to modern Iran, the obstacles confronting President Donald Trump are hardly surprising.
Following dozens of wars between the ancient empires of Rome and Persia, peace accords frequently failed to resolve underlying tensions and occasionally exacerbated them.
Lurching from Conflict to Conflict
The formidable empires of ancient Persia—ruled first by the Parthians (247 BCE – 224 CE) and later by the Sasanians (224–651 CE)—rivaled Rome for centuries. Their intermittent warfare produced treaties that served primarily as mechanisms to buy time.
The first major clash came in 53 BCE, when the Roman general Crassus launched a disastrous invasion. Crassus perished, and legions were annihilated on the plains near Carrhae in southern Turkey.
Emboldened by ongoing conflict, the Parthians compelled Rome in 20 BCE to recognize the Euphrates River as a boundary. For an empire accustomed to unchecked expansion, this concession marked a significant psychological and strategic shift.
Hostilities erupted again in the mid-first century CE over the Kingdom of Armenia, a strategic buffer state situated in modern-day Armenia and eastern Turkey.
Following that war, Emperor Nero and Parthian King Vologases I concluded the Treaty of Rhandeia in 63 CE. The accord stipulated that the Armenian monarch would be nominated by the Parthians but crowned by the Roman emperor. While the treaty settled the immediate dispute, its mechanisms grew unwieldy over time.
When the Parthians later disregarded the agreement, Emperor Trajan launched a punitive invasion in 114 CE. Despite initial successes, including the capture of the Parthian capital, the campaign collapsed; all gains evaporated by Trajan’s death in 117 CE.
Conflict intensified after the Sasanians replaced the Parthians in 224 CE. Control of Armenia remained a persistent flashpoint and a central component of subsequent peace settlements.
After Emperor Gordian III died during an invasion of the Sasanian Empire in 244 CE, a new settlement imposed financial penalties on Rome and barred Roman interference in Armenia.
Rome violated the treaty within years, triggering devastating Sasanian counter-offensives and the capture of Emperor Valerian in 260 CE.
The statue, titled Kneeling Before Iran, shows the emperor grovelling before Persian king Shapur I. Where did this imagery come from? And why now? @Macquarie_Uni https://t.co/R7tMVBzxNf
— The Conversation – Australia + New Zealand (@ConversationEDU) November 10, 2025
Rome exacted revenge in the late 290s with a significant victory over King Narseh. The ensuing Treaty of Nisibis (299 CE) extended Roman influence eastward and granted Rome control of Armenia.
Yet this treaty sowed deep enmity. When Shapur II invaded Roman territory in the 350s, his primary objective was to repudiate the 60-year-old accord. That hostility was reinforced when Emperor Julian invaded the Sasanian Empire and suffered a catastrophic defeat—including his own death—in 363 CE.
While the fifth century CE saw a relative lull, the sixth and seventh centuries witnessed near-constant warfare between the two powers.
Numerous treaties were attempted, but none endured. Perhaps the most futile was the so-called “Eternal Peace” of 532, which collapsed in less than eight years.
Easier to Make War Than Peace
History demonstrates that peace deals, however celebrated at signing, can plant the seeds of future discord.
The Roman-Persian contest over Armenia was finally resolved in the 380s through a partition agreement—but only after more than 400 years and dozens of failed attempts.
An unending cycle of conflict, invasion, brinkmanship, and stalemate defined the intervening centuries.
Does a lasting diplomatic arrangement between the United States and Iran face similar prospects? Only time will tell. One hopes this iteration will not require centuries to achieve stability.
