The Iran-Afghanistan Border: A Complex Geopolitical Nexus

Afghanistan and Iran are neighbouring countries with a complex and extensive shared history. Afghanistan was part of many Persian Empires, and the two countries have had official relations since 1935. However, they have had a tumultuous relationship, with border disputes, water rights issues, and conflicting political interests causing tension.

Afghanistan and Iran share a 585-mile border, and both countries have accused each other of initiating violence and providing support to opposing factions. In 2023, deadly clashes broke out between the two countries' border guards, resulting in casualties on both sides.

In addition to border disputes, Iran and Afghanistan have disagreed over water rights to the Helmand River, which flows from Afghanistan into eastern Iran. A 1973 treaty outlines water-sharing agreements, but both countries have accused the other of violating its terms. Climate change and drought have exacerbated this issue, with water scarcity becoming an increasingly critical problem in the region.

Afghanistan and Iran also have differing political interests. Iran is a Shia theocracy, while Afghanistan is predominantly Sunni. Iran has viewed Afghanistan as a haven for Sunni extremists and has interfered in Afghan politics through proxies. The countries' relationships with the US and NATO have also been a source of tension.

Despite the complexities of their relationship, Afghanistan and Iran also have strong cultural ties and economic interdependence. Many Afghans speak Persian, and both countries celebrate Nowruz, the Persian New Year. They are also major trading partners, with Afghanistan relying on Iran for imports ranging from construction materials to electricity.

Iran and Afghanistan have had a long history of relations, with ties existing for millennia

Afghanistan and Iran share a relatively long history, and Afghanistan was part of many Persian Empires, including the Achaemenid and Sasanian dynasties. The two countries also share ethnic, linguistic, and religious links, with many Afghans speaking Persian and celebrating Nowruz, the Persian New Year. Dari, an eastern dialect of Persian, is one of the official languages of Afghanistan.

Despite these long-standing connections, the relationship between Iran and Afghanistan has been complicated and fraught with tension at times. One significant source of tension has been Iran's interference in Afghanistan through proxies, as well as its opposition to the United States, a strong partner of the Kabul regime. Iran has also had a history of ideological differences and political rivalry with the Afghan Taliban, particularly during the Taliban regime in the late 1990s, when Iran supported the anti-Taliban Northern Alliance.

In recent years, Iran has pursued a risky policy of "hedging" in Afghanistan, providing support to both the Afghan government and the Taliban to keep them divided and influence political developments. Additionally, Iran has been accused of supplying weapons to the Taliban, creating confusion about its true intentions and contributing to the complex nature of their relationship.

Another dimension of Iran's approach to Afghanistan is shaped by its perception of its relations with Washington. Iran has long viewed the U.S. military presence in Afghanistan as a threat and has sought to counter U.S. influence in the region. This has created common ground between Iran and the Taliban, as they share a mutual interest in countering U.S. influence in Afghanistan.

Iran has also played a pivotal role in Afghanistan's post-Taliban development, providing foreign investment and assistance in critical areas such as infrastructure, road construction, energy supply distribution, and agricultural and communications development. However, the relationship between the two countries continues to be complex and ambiguous, with Iran's true intentions and long-term goals in Afghanistan remaining a subject of debate.

The two countries share a border of about 580-585 miles

Afghanistan and Iran have a long history together. The two countries share a border of about 580-585 miles. The border traverses a generally arid, inhospitable region with few inhabitants, except in the Zabol-Zaranj area where the main border crossing is located.

The border between the two countries was formalised in the period 1872-1935 by a series of third-party arbitrations, stemming from the Treaty of Paris (1857) in which Persia and Afghanistan agreed to refer any dispute between them to Britain for arbitration. A rough delimitation was proposed in 1872 by a committee headed by Sir Frederic John Goldsmid following a line from Banda to Kuh-i-Malik Siah (a hill at the modern Afghanistan-Iran-Pakistan tripoint) via the Helmand River.

The Goldsmid boundary proved to be inadequate, especially given the shifting of the course of the Helmand River, and thus a more precise boundary was drawn up in three sections over the following decades: the northern section by General C.S. MacLean, British consul general for Khorasan and Sīstān, in 1888-91; the southern section by Colonel Sir Henry McMahon in 1903-05; and finally, the middle section by Turkey's General Fahrettin Altay in 1934-35. After each demarcation, boundary pillars were erected, leading to a total of 172 pillars in the non-riverine sections of the border.

The boundary itself was not disputed after 1935, but disputes over the allocation of water resources in the region continued for many years and were not finally resolved until 1973.

The two countries have a relatively strong relationship today, but tensions persist over Iran's interference in Afghanistan through proxies. Since 1979—the year of Iran's revolution and the Soviet invasion of Afghanistan—relations between Tehran and Kabul have ebbed and flowed.

In recent years, there have been several clashes between the two countries along the border. In May 2023, armed forces of the Islamic Emirate of Afghanistan and Iranian border guards clashed along the Afghanistan-Iran border between the Afghan Nimruz Province and the Iranian Sistan and Baluchestan Province. The clash resulted in the death of one Taliban soldier and two Iranian guards.

Afghanistan was part of many Persian Empires, including the Achaemenid and Sasanian dynasties

Afghanistan and Iran have had relations for millennia, and Afghanistan was part of many Persian Empires, including the Achaemenid and Sasanian dynasties.

The Achaemenid Persian Empire was founded by Cyrus in the 6th century BCE. Shortly after his conquests of Media, Lydia, and Babylonia, Cyrus marched into Gandhara (in modern-day Pakistan) and annexed it into his empire. By 550 BCE, the Persians had replaced Median rule with their dominion and began expanding past previous Median imperial borders. By the 4th century BCE, Persian control of outlying areas had become somewhat tenuous, and distant provinces like Balkh were often restless under Achaemenid rule. The last Achaemenid ruler, Darius III, tried to flee to Balkh but was assassinated by Bessus, a subordinate lord. Bessus proclaimed himself the new ruler of Persia, but he was unable to resist Alexander's advancing army and was overthrown. Alexander's invasion marked the end of Achaemenid rule in Afghanistan.

Under the Sasanian dynasty, Shapur I extended his authority eastwards into Afghanistan, and the previously autonomous Kushans accepted his suzerainty. Sasanian cultural expansion followed this victory, and their art penetrated Turkistan, reaching as far as China. Shapur II pursued a harsh religious policy, completing the collection of the Avesta, the sacred texts of Zoroastrianism, and persecuting Christians and heretics. During the reign of Shapur II, the Sassanids lost control of Bactria to the Kidarites, Hephthalites, Alchon Huns, and Nezaks—the four Huna tribes that would go on to rule Afghanistan. Sasanian influence on the Kushans was primarily limited to the conception of kingship, which spread through the trade of Sasanian silverware and textiles depicting emperors.

The countries have had disputes over water rights to the Helmand River since the 1870s

Afghanistan and Iran have had disputes over water rights to the Helmand River since the 1870s. The river, which flows from Afghanistan to eastern Iran, is a critical source of water for both countries. It is used for agriculture, fishing, and human consumption by millions of people on both sides of the border.

The dispute first arose when a British officer drew the Iran-Afghan border along the main branch of the Helmand River during the period when Afghanistan was a British protectorate. In 1939, the governments of Iran and Afghanistan, led by Reza Shah Pahlavi and Mohammad Zahir Shah respectively, negotiated a treaty on water allocation, which the Afghans never ratified.

The dispute intensified in the 1950s when Afghanistan built two dams on the Helmand River—the Kajaki and the Grishk—which restricted water flow into Iran. Renegotiations continued until 1973, when the prime ministers of Iran and Afghanistan signed a water-sharing treaty. However, this treaty was also not ratified or implemented.

In recent years, the dispute has escalated due to several factors. Firstly, Afghanistan has continued to build dams on the Helmand River, including the Kamal Khan dam, which was inaugurated in March 2021. These dams have further reduced water flow into Iran, impacting Iranian regions such as the Hamoun wetlands, which have nearly dried up due to restricted water flow, unsustainable dam constructions, and the introduction of invasive fish species. Secondly, Iran has accused Afghanistan of failing to adhere to the 1973 treaty and has opposed the construction of new dams. Thirdly, both countries have faced periodic droughts, which have further exacerbated the issue.

In May 2023, tensions escalated when Iranian President Ebrahim Raisi warned the Taliban rulers of Afghanistan not to violate Iran's water rights, as stipulated in the 1973 treaty. Clashes broke out between Iranian and Afghan border guards, resulting in casualties on both sides. Despite these clashes, both countries have expressed a desire to de-escalate the situation and resolve the dispute diplomatically.

Iran has had complicated relations with the Taliban since the group emerged in the 1990s

Iran has had a complex relationship with the Taliban since the group emerged in the 1990s. The two nations have historically had volatile relations, with Iran, a predominantly Shia country, and the Taliban, dominated by Sunni fundamentalists, holding opposing ideological and political views.

In the late 1990s, Iran almost went to war with the Taliban after the group raided the Iranian consulate in Mazar-i-Sharif, killing nine Iranians. This incident led to a military mobilisation by Iran, which was only resolved through UN mediation. During the 2001 US invasion of Afghanistan, Iran cooperated with US forces and supported the Northern Alliance against the Taliban.

However, as US and NATO forces remained in Afghanistan, Iran's relationship with the Taliban shifted. Viewing the Taliban as a tool to counter US influence on its borders, Iran provided military equipment to the Taliban, enough to pressure the US but not enough to provoke a military response.

In recent years, border clashes and disputes over shared water resources have escalated tensions between Iran and the Taliban. Climate change has severely impacted water resources in both countries, and ineffective governance has led to a lack of effective regulations and environmental protection policies.

Despite their differences, Iran and the Taliban have found common ground in their opposition to the presence of US troops in Afghanistan and the rise of ISIS-K, a local affiliate of ISIS. Iran's fear of ISIS-K far exceeds its concerns over the Taliban, which it sees as a force capable of countering the extremist movement.

Additionally, Iran has been pursuing a "hedging" policy in Afghanistan, providing support to both the Afghan government and the Taliban to keep them divided and influence political developments. Iran's dual approach makes it challenging to analyse its intentions and influence in the region.

While the Taliban has sought to improve its image and accommodate Iran to expand its diplomatic support, many Iranian voices remain skeptical of the group's true intentions. The Taliban's violent tactics and denial of responsibility for attacks in Afghanistan have led to distrust among the Afghan public and international stakeholders.

Overall, Iran and the Taliban's relationship has been complex and marked by shifting alliances, shared interests, and ideological differences.

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