'Iran and Iraq also have a unique relationship with each other. The neighbors hold regular security meetings, underlining their ongoing ties. Meanwhile, the Pentagon accuses Iran of supplying militias in Iraq with improvised explosive devices — particularly the especially lethal armor-piercing variety.
Given that Iran is predominantly Shiite and now ruled by a theocratic government, in contrast to Iraq where Sunnis, until the U.S. invasion, long ruled the Shiite majority, the schism between the major branches of Islam has played a major role in relations between the countries. This split dates back to disputes over the succession to the Prophet Mohammed. For the Shiites, Mohammed's son-in-law Ali was the rightful heir to the Prophet, while the Sunnis followed his father-in-law Abu Bakr, who became the first Caliph.
And while ethnically and linguistically distinct — Iran’s population is predominantly Persian and Farsi-speaking, while Iraq’s is dominated by Arabic-speaking Arabs — the two share an intertwining history and a border spanning about 1,000 miles.
Different but next door
The history of Iran, formerly known as Persia, spans many centuries. Its rulers battled the ancient Greeks and its series of empires have stretched as far as western and central Asia and the Caucasus Mountains.
In contrast, Iraq as part of the larger Arab "nation" has been a recognized and distinct country for a much shorter time. Even so, the area known for centuries in Europe as Mesopotamia has in the region been referred to as al-‘Iraq — the shore of a great river and the grazing land around it — since about the eighth century.
Sunni vs. Shiite
It has been Iraq’s fate to be caught in the middle between Persia and subsequent competing powers, according to Middle East expert Dr. Jubin Goodarzi, the author of the "Syria and Iran: Diplomatic Alliance and Power Politics in the Middle East."
“Both during the Romans and the Ottomans, Iraq became a battleground of empires," he says.
An important turning point for both came in 1501 when Shiite Islam became the state religion in Persia (Shiite Islam is distinct from the religion’s other major branch, Sunni Islam). Najaf and Karbala in Iraq, two of Shiite Islam’s most important centers, for which Iran pays for much of the upkeep, are still visited by thousands of Iranian pilgrims and clerics every year, as well as local Iraqi Shiites.
During the 16th and 17th centuries, Iraq became part of the Sunni Ottoman Empire, which stood in contrast to Persia’s Shiite one. Ottoman control over Iraq waxed and waned over the centuries but was finally relinquished in the years following the end of World War I in 1918 and the empire’s subsequent dismantlement. While Iraq was considered a backwater province during Ottoman times, Sunnis were elevated as the local ruling class. The British followed suit.
The victorious European powers carved up Ottoman holdings, with the British occupying the cities of Baghdad, Mosul and Basra in Iraq. In 1920, the League of Nations granted the United Kingdom the mandate for Iraq, and borders were drawn between the countries with little consideration to the communities being split up by them. Subsequent revolts were suppressed and Prince Faisal bin Husain al-Hashemi was placed on the throne within two years.
In 1932, the League of Nations granted Iraq its independence, although Britain left Iraq’s Sunnis very much in charge.
Path to revolution
During World War I, Persia was the scene of intense fighting despite having declared its neutrality, and the decades between the wars were also defined by great political tumult. By 1941, by which time it had changed its name to Iran, the country had sided with the Axis powers, leading to a brief Anglo-Russian occupation of the country at the end of the war.
Its great size, natural resources and, especially, its strategic position on the Caspian Sea ensured that Iran would be a battleground between the Soviet Union and the United States early on in the Cold War.
In 1950, nationalist Mohammad Mossadeq became prime minister of Iran, which led to tension with pro-Western Shah Mohammad Reza Pahlavi, who fled the country to Iraq in 1953. Later that same year, the intelligence services of Britain and the United States, which feared that Tehran might turn toward Moscow during that crucial stage of the Cold War, helped engineer a coup that deposed Mossadeq and reinstalled the shah.
While there was some tension between Iran and Iraq in the 1940s and 1950s, the countries were mostly governed by conservative, pro-Western regimes.
That changed dramatically in 1958 when a military coup deposed Iraq’s monarchy and established a republic. The secular Sunni government became a center of Arab nationalism, and in the following years struggled to grapple with and suppress its Kurdish minority and largely disenfranchised Shiite majority. Iran maintained ties to both restive groups during this time.
1979: A catalyst
The year 1979 was momentous for both Iraq and Iran. In Iraq, Saddam Hussein consolidated his rule of the Baath Party in a bloody putsch that eliminated possible competitors.
It was also the year that the shah and his family were forced into exile and the Iranian revolution installed a theocratic state led by Khomeini. Following the abduction of 52 American hostages in the U.S. Embassy in Tehran, the country found itself largely isolated internationally. (The hostages were released after 444 days.)
The toppling of the shah’s secular, pro-Western regime had a major impact not only on Iran’s standing in the world but also its relations with Iraq.
“The Iranian revolution was a catalyst, and it changed the equation overnight,” says Goodarzi. Saddam benefitted by convincing the West that he was a follower of the foreign policy doctrine that "my enemy’s enemy is my friend" and shored up support for his rule internationally.
From that time on the relationship between the two countries was defined by Iraq's Baathist secular Sunni government versus Iran's theocratic Shiite one, he says, although several events paved the way to hostilities breaking out.
In 1980, an Iran-backed militant Shiite group tried to kill Iraq's foreign minister, Tariq Aziz, and was suspected of trying to kill the minister of culture and information. The response was swift and ruthless: more than 40,000 Shiites of Iranian origin were deported. The government later executed Shiite religious leader Ayatollah Sayyid Mohammad Baqir al-Sadr, and his sister, Bint al-Huda.
During this time, Saddam tried and failed to sever the close ties between the religious hubs of Najaf and Karballah in Iraq and Qom in Iran.'