The Iran Factor in Afghanistan

In recent years -- and especially in recent weeks, amid the alarmingly rapid gains of the militant group known as the Islamic State in Iraq and Syria (ISIS) -- much ink has been spilled about the role that Iran plays in neighboring Iraq.

Considerably less has been said about the role Iran plays in Afghanistan, another of Iran's neighbors, and the country where the United States has waged its other post-9/11 war. In the West, what has been said has largely depicted Tehran's Afghan policies as deleterious, not to mention divergent with American interests. U.S. and NATO officials have accused Tehran of providing weaponry to the Afghan Taliban. In 2007 and 2011, international forces in Afghanistan intercepted Iranian arms shipments destined for the Taliban.

In 2010, the New York Times revealed that Tehran was literally handing bags of cash to Hamid Karzai's deeply trusted chief of staff, Umar Daudzai -- part of an effort to "drive a wedge" between Afghans and Americans.

More recently, in May, the Wall Street Journal reported that Iran was hiring Afghan Shias to fight in Syria on the side of President Bashar al-Assad. Some Middle East militancy experts believe this has been happening for nearly two years.

Yet, despite all of this, the role Iran plays in Afghanistan is relatively constructive. U.S. and Iranian interests in the country (such as stability) are for the most part convergent. Tehran can help advance these interests in post-2014 Afghanistan -- and especially if long-fraught relations with Washington continue to improve.

Tehran has a history of helping the U.S. government in Afghanistan. During the Bonn conference in late 2001, it was Iran that broke a stalemate over the composition of Afghanistan's first post-Taliban government. James Dobbins, the U.S. representative at Bonn, has recounted how the Iranian representative, current foreign minister Javad Zarif, had a brief whispered conversation with the Northern Alliance representative, Younis Qanooni, in the corner of the negotiating room. A minute later, Qanooni returned to the table and a deal was reached.

Tehran and Washington have also cooperated to counter the Taliban and al Qaeda. In the initial years after international forces arrived in Afghanistan in 2001, according to reportage by journalist Barbara Slavin, Tehran arrested al Qaeda figures on its soil and gave Washington maps showing Taliban positions in Afghanistan. According to Dobbins, Iran's military also offered to train 20,000 Afghan troops as part of a U.S.-led program to rebuild Afghanistan's army. This collaboration could have gone even further. In 2003, Tehran made a formal offer to open comprehensive negotiations with Washington, but it was ignored by the George W. Bush administration. Afghanistan had been one of the agenda points.

Such cooperation shouldn't be surprising. When it comes to Afghanistan, Tehran and Washington tend to see eye to eye on many core issues, including the Taliban. Despite the arms that Tehran has supplied to the group, Shia Iran recoils at the thought of an Afghanistan once again led by the Sunni Taliban. And yet, sectarian concerns aren't the sole reason why.

In 1998, the Taliban killed nine Iranian diplomats in an attack on Iran's consulate in Mazar-e Sharif. In response, Iran mobilized 200,000 troops on its border with Afghanistan and nearly went to war. Little wonder Tehran (which never recognized the Taliban government) was outspoken in its opposition to Taliban rule. These anti-Taliban views haven't changed today. One Iranian expert told me that Tehran is terrified about the prospect of being sandwiched by ISIS to its west and the Taliban to its east.

Then there is the drug factor: The Taliban insurgency is funded in large part by narcotics trafficking, and Iran is a chief destination. This illicit trade fuels Iran's acute drug crisis. Iran has one of the world's largest drug use rates, and suffers from a major heroin epidemic.

So why would Iran provide arms to a group that it so vigorously opposes? One explanation, taking into account the period of uncertainty sure to accompany the international troop drawdown, is a desire to hedge its bets and to remain in the good graces of all key Afghan political players, including Afghanistan's chief Pashtun militant organization. Another explanation, however, is Iran's fear that the United States could one day use Afghanistan as a staging ground for attacks on Iranian nuclear facilities. Better U.S.-Iran relations (and fewer U.S. troops in Afghanistan) could reduce Iranian incentives to aid the Taliban.

There's good reason to believe that Tehran wants a stable Afghanistan. Greater instability would intensify narcotics trafficking. Additionally, it would lead to further influxes of Afghan refugees (only Pakistan has more). In recent years, these immigrants have been increasingly unwelcome in Iran, and many have been deported. Tehran also likely worries that a deteriorating Afghan security environment would embolden anti-Shia forces, including the Pakistani organization Lashkar-e-Jhangvi, whose commanders vow to march into Afghanistan when international troops depart. Though Iran publicly opposes any U.S. troops in Afghanistan, in private it would probably happily accept the presence of a residual post-2014 force.

Tehran also shares the U.S. objective of an Afghanistan that is more integrated with South and Central Asia. Iran has pursued rail, pipeline, and trade projects meant to better link Central Asian states. It is also cooperating with India on the construction of a port that would facilitate more Indian trade with Afghanistan and Central Asia (the Chabahar port would enable India to bypass longer routes through Pakistan). These efforts dovetail with Washington's "New Silk Road" initiative, which aims to develop regional energy markets in South and Central Asia and more broadly to boost cross-border trade and transit across these regions. However, U.S. sanctions on Iran have prevented Tehran from obtaining international financing for some of its projects. Phasing out these sanctions -- a possible upshot of improved bilateral relations -- could bring in more financing, and allow regional integration initiatives to truly take off.

Like many of Afghanistan's neighbors, Iran is actively engaged in the country, spurred in part by shared cultural ties. The Afghan city of Herat was part of Iran until 1857. Dari, one of Afghanistan's two official languages, is a dialect of Iran's official language of Farsi. Tehran is a major economic player in Afghanistan; the $540 million it pledged at a donors conference in 2002 was the largest amount of any non-Organization for Economic Cooperation and Development (OECD) state. It exports a variety of critical goods to Afghanistan -- including food, medicine, and oil -- and provides $50 million in annual anti-narcotics aid. Bilateral trade more than doubled between 2011 and 2013. Iran watchers tell me that Tehran could increase its economic assistance in an effort to promote stability in post-2014 Afghanistan.

Iran wields considerable influence in Afghanistan, particularly among Shias, who comprise about 20 percent of the total population. However, according to a new RAND study, Iran seeks to extend its reach beyond Shias. Tehran funds Afghan NGOs, schools, and media institutions. It has also cultivated ties with Pashtun Islamist groups, from Hezb-e Islami to the Taliban.

The results of this outreach are mixed. Some Afghans, particularly Shias, support Iran's presence. Yet others are resistant. Many residents believe Iran is guilty of excessive meddling in local affairs. Some Afghan Shias even accuse Iran of radicalizing -- and attacking -- their communities (Afghan security officials have blamed Iran for launching "terror activities and propaganda"). This all helps explain why even a seemingly innocuous Iranian plan to build a new hospital in Bamiyan province (a heavily Shia region) is sparking strident local opposition. (Afghanistan, incidentally, has not been included in recent polls that highlight global views of Iran).

Nevertheless, Iran is poised to be one of the most influential regional players in post-2014 Afghanistan. Beijing, despite its important economic role, keeps a low political profile. Islamabad has poor relations with Kabul, and its sway over the Afghan Taliban may be exaggerated. Even New Delhi, which has signed a strategic agreement with Kabul, will limit the scope of its activities due to threats from anti-India militant groups that regularly attack Indian interests --including the embassy in Kabul and consulate in Jalalabad. Iran, by contrast, is deeply engaged both politically and economically.

Ultimately, the extent to which Iran plays a stabilizing role in Afghanistan's future will depend on numerous factors. Will Iran's Afghan diplomacy and assistance be truly inclusive, or will it be largely sect- and ethnicity-based, thereby risking polarization and destabilization? Is Tehran capable of maintaining cordial relations with Kabul in the post-Karzai era, given the strong personal relationship Iran's leaders enjoyed with Afghanistan's outgoing president?

Perhaps most significant, however, is the trajectory of U.S.-Iran ties. In the event of a warming pattern, Tehran will likely curtail its actions in support of the Taliban. Yet, if bilateral relations lapse or worsen, expect such actions to ramp up.

The outcome of the ongoing negotiations over Iran's nuclear program (the deadline for a deal is July 20) could serve as a bellwether of the nemeses' ability to reconcile and, by extension, of prospects for greater stability in Afghanistan.

This article originally appeared on ForeignPolicy.com