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How Diaspora Communities Influence Terrorist Groups

James A. Piazza
Sunday, March 3, 2019, 10:00 AM

Editor’s Note: Terrorist groups often draw on ethnic or religious brethren in other countries. These communities raise money, provide arms, offer volunteers, lobby host governments and otherwise try to advance the terrorist cause. James Piazza of The Pennsylvania State University goes deep on diasporas. He identifies the ways in which they make a terrorism problem worse and why fighting terrorism requires countering the influence of militant diasporas.

Daniel Byman


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Editor’s Note: Terrorist groups often draw on ethnic or religious brethren in other countries. These communities raise money, provide arms, offer volunteers, lobby host governments and otherwise try to advance the terrorist cause. James Piazza of The Pennsylvania State University goes deep on diasporas. He identifies the ways in which they make a terrorism problem worse and why fighting terrorism requires countering the influence of militant diasporas.

Daniel Byman


Ties between terrorist groups and diaspora communities are not a recent phenomenon. In the late 19th century, anti-tsarist anarchist terrorist movements nurtured connections with networks of supporters among Russian and Eastern European immigrant communities in the United States. Throughout most of the 20th century, the Irish Republican Army (IRA) enjoyed close links with the Irish-American community. The EOKA (National Organization of Cypriot Struggle) terrorist movement, which sought the independence of Cyprus from British administration, forged close links with the international Greek diaspora. In the 1970s, Armenian communities in multiple countries were closely tied with groups like the Armenian Secret Army for the Liberation of Armenia (ASALA) and the Justice Commandos of the Armenian Genocide. More recently, organizations such as Hamas, Hezbollah, the Liberation Tigers of Tamil Eelam (LTTE), and the Kurdistan Workers’ Party (PKK) have been sustained by Palestinian, Lebanese Shiite, Tamil, and Kurdish diasporas in multiple countries. In the aftermath of two deadly terrorist attacks in Spain in August 2017 perpetrated by a cell of Moroccan-born immigrants inspired by the Islamic State, authorities and commentators noted the importance of North African diaspora communities in Spain and elsewhere in Europe for terrorist movements both in Europe and abroad.

Scholars have noted that terrorist groups frequently draw on diaspora communities for various types of support. Gabriel Sheffer, an expert on diaspora politics, notes that out of the 50 most active terrorist organizations after 1945, 27 were closely associated with global diaspora communities. In a separate study of 87 insurgent groups engaged in terrorism from 2008 to 2013, international security expert (and Foreign Policy Essay editor) Daniel Byman estimated that 38 (approximately 44 percent) relied on support from transnational diaspora communities for their operations.

Despite the importance of diasporas to terrorist groups, the role they play is often neglected or misunderstood. These external communities can be an important form of support, but, as I demonstrated in a recent study, the type of support can make a large difference in the benefit the terrorist group receives. Additionally, this support can also influence the terrorist group and condition its political policies.

The Appeal of Diasporas to Terrorist Groups

The term “diaspora” can be defined in different ways, but most experts regard diasporas as ethnic or sectarian communities that permanently reside outside of their homeland in another country. Though living abroad, diasporas maintain connections with their homeland and continue to identify with it. Diaspora communities often remain engaged in the current affairs of their homelands and often exert considerable influence over their politics, public policy and economy. Diasporas are frequently distinguished from “migrant communities” by their permanence and the enduring importance of “the homeland” to their identities as communities.

Because of this influence, terrorist movements often forge close links with diaspora communities. Diasporas can provide a host of material and other benefits to terrorist organizations. For example, terrorist actors frequently look to diaspora communities as pools of potential volunteers and recruits. Historical terrorist organizations, such as the Irgun and Lehi, recruited extensively from Jewish diaspora communities in Eastern Europe and the Soviet Union while engaged in terrorist campaigns against British authorities during the Palestinian mandate in the 1940s. This is a pattern that extends to terrorist organizations today. Many Islamist terrorist organizations, including the Islamic State and al-Qaeda, have similarly recruited members from among communities of Muslims living in Western Europe and North America.

Many diaspora communities have become financially successful in their adopted countries. This makes them well positioned to provide material help to terrorist groups. Nearly all diaspora-linked terrorist movements rely on diaspora communities to raise money and acquire weapons. Perhaps the most familiar example to Americans would be the fundraising efforts of Irish-American communities on behalf of the IRA throughout the 20th century. Often, diaspora financial support makes up the lion’s share of a terrorist movement’s operating revenue. For example, though Hamas received support from Saddam Hussein’s Iraq during the 1990s, currently receives state support from Iran and levies taxes on citizens of Gaza, a substantial source of revenue is believed to be from Palestinians living abroad.

Diaspora communities are also frequently active in politics in their countries of residence. This political capital is crucial to terrorist movements. Diasporas can lobby governments for policies that are favorable to certain terrorist groups, and can engage in public relations campaigns that help affiliated terrorist groups get their message to a broader public. This sort of grassroots communication is particularly useful for terrorist movements operating in countries with media censorship. Terrorism expert Peter Chalk provides a detailed study of how the influential Tamil diaspora in Canada and the United Kingdom extensively propagandized on behalf of the LTTE throughout the 1990s and early 2000s. In addition to producing sophisticated pro-LTTE propaganda, Tamil community members helped the LTTE overcome government censorship on the ground in Sri Lanka and worked to highlight human rights abuses committed by the Sri Lankan government in its campaign against the LTTE.

Finally, in a more general sense, diasporas can help terrorist movements internationalize their struggles. This provides terrorists with more flexibility and critical strategic advantages. The 2017 Islamist terrorist attack in Spain helps to illustrate this. In the aftermath of al-Qaeda-inspired suicide bombings in Casablanca in 2003, the Moroccan government cracked down severely on violent Islamist extremism. This made Morocco a more difficult environment for Islamist terrorist organizations, which subsequently shifted their attacks to Western Europe and were aided by the cover and support provided by extremist, fringe elements of the Moroccan diaspora community in Spain and elsewhere.

How Diasporas Affect Terrorist Groups

Many terrorist groups clearly benefit from, and even rely on, diaspora communities. But with that support can come influence that affects whether a terrorist group will continue to function and even how it behaves. In a recently published study, I examined the effects diasporas have on the terrorist groups with which they are linked. Based on data on the diaspora relationships of 586 terrorist movements identified by the RAND Corporation for the period 1970 to 2007, I found that specific types of support correspond to longer lifespans for terrorist groups and may affect their actions.

Terrorist movements linked with diaspora communities have higher survival rates. Specifically, I found that diaspora-linked terrorist movements were more than 40 percent less likely to terminate as organizations than unaffiliated terrorists in any given year, holding all other factors constant. Diaspora connections appear to help terrorist groups resist government efforts to crush them militarily and to police them out of existence. I also found diaspora-linked terrorists to be about 40 percent less likely to terminate due to military or police force than terrorist groups without diaspora connections. While diaspora ties seemed to protect organizations from external threats, they do not appear to enhance the internal resilience of terrorist movements. Both diaspora-linked and unaffiliated terrorist organizations seem to end by splintering or fracturing internally at the same rate.

Additionally, diasporas seem to impede terrorist organizations from transforming into nonviolent political parties. Diaspora-linked terrorists were 34 percent less likely to terminate by agreeing to give up armed struggle and become an unarmed political party or organization. This finding is consistent with the contention that diasporas are often “peace-wreckers” when it comes to civil conflicts in their homelands. Scholars have argued that because they are usually sheltered from the direct physical consequences of conflict in their homelands, diaspora community members are more likely than counterparts in their homelands to adopt purist and maximalist positions in civil conflicts. This may explain why diaspora links prompt terrorist movements not to seek nonviolent offramps.

Finally, the benefits of some types of support from diaspora communities seem greater than others for the longevity of terrorist groups. Material support, which includes the provision of weapons and funding, correlated with better survival rates for terrorist groups. Other forms of political support, including lobbying and public relations campaigns, did not have a discernible effect on terrorist organizations’ lifespans.

These findings have implications for counterterrorism policy. They suggest that depriving terrorists of the material support that diasporas can provide should make them easier to defeat militarily or police out of existence. In addition, separating terrorist movements from their supporters in the diaspora might increase the chance that movements will opt to end armed struggle in favor of engaging in nonviolent politics. Counterterrorism may begin at home, but incorporating it into a broader foreign policy is often vital.

James A. Piazza is Liberal Arts Professor of Political Science at The Pennsylvania State University. Piazza’s research investigates terrorism, its causes and consequences, militant organizations, counterterrorism policy, and politics in the Islamic world.

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