The Tsarnaev brothers’ brutal attack in Boston sparked renewed interest in terrorism in Eurasia. The subsequent disclosure that two students from Kazakhstan allegedly tried to hide incriminating evidence against Djokhar Tsarnaev has only heightened that interest. The not-guilty plea of Fazliddin Kurbanov, the alleged Uzbek terrorist in Idaho, underscores the new threat.

And that’s a good thing. Understanding what was and is happening in Eurasia can help us better fight terrorism and prevent future attacks rooted in that region.

Chechens and Uzbeks fought in Afghanistan with the Taliban, and fighters from the North Caucasus are involved in Syria on the side of Sunni extremists despite Russia’s support of the Assad regime. But until the Tsarnaev and Kurbanov cases, no Muslims from the ex-USSR were involved in U.S.-based terror attacks.

Most North Caucasus migrants and their communities back home bear no enmity to America. However, many carry with them the historic trauma of czarist oppression and ethnic cleansing, as well as the 1944 genocidal expulsion to Siberia and Central Asia.

Tens of thousands of immigrants from historically Muslim Eurasian areas in the former USSR came to the United States in the wake of violent conflicts that flared after the Soviet collapse. These were bloody wars. Over 200,000 people were killed in the fighting between Chechnya and Russia (1994-1996 and 1999-2005), between Armenians and Azerbaijanis in Nagorno-Karabakh (1988-1994), and in the civil war in Tajikistan (1992-1997). Hundreds of thousands became refugees, and many emigrated.

Religion and ideology in these diasporas have undergone a generational change. Those who grew up in the Soviet Union often neglected religious observance. The atheist state persecuted the clergy (whether Muslim, Christian, or Jewish), and in Eurasia most Muslims ignored the taboo on alcohol and were lax about maintaining the dietary laws (halal), while neglecting the study of the Quran and other scriptures.

Today the situation is different. Many American-raised Muslims from Eurasia are socializing with U.S. peers who have higher levels of Islamic consciousness and observance. This includes many peers from Pakistan and the Arab world. Saudi-supported Salafi and other radical schools and madrassas (religious academies) have welcomed them. And Internet propaganda by radical clerics, such as that found on the Tsarnaev brothers’ computers, is available to all.

The “homeland” factor also plays a significant role. The Tsarnaev brothers were raised on stories of Russian atrocities in Chechnya. They were named after a great Islamic conqueror (Tamerlane) and possibly after Djokhar Dudayev, the first president of secessionist Chechnya.

The stories of Islamist fighters influenced both brothers, especially Tamerlan. He travelled to the region, where firefights between Russian security forces and Islamist fighters claim hundreds of victims a year. In the six months he spent there, he met with a relative, a prominent Islamist, as well as with “mujahedeen” whom he befriended over the Internet. Tamerlan was also in touch with a Chechen rebel leader residing in the U.S. Zubeydat, their increasingly Islamist mother, certainly did not help moderate Tamerlan’s views.

The Tsarnaev case is not unlike those of Palestinian-American Maj. Nidal Hassan, the alleged Ft. Hood shooter, or the U.S.-raised, Salafi-indoctrinated Somali teens who journeyed to their ancestral homeland to fight and die for Al Qaeda-supported Al Shabab. For some within these immigrant groups, conflicts in the country of origin and global Islamist propaganda have combined to create an explosive mix.

The case of the Kazakh students who allegedly aided and abetted Djokhar Tsarnaev after the attack is less dramatic. There is no reported evidence that these 19 year olds understood the enormity of the crime the Tsarnaev brothers had committed, nor is there evidence that they participated in an Islamist cell or were sympathetic to the cause of jihad.

Kazakhstan is secular, multi-ethnic and multi-denominational. While there is a growing, but still relatively small, presence of Islamist cells, the majority of the country is more interested in economic development than in militant politics. The government of Kazakhstan has sent over 6,000 students to study overseas through the Bolashak (“Future”) program, and many top Kazakh officials graduated from leading American universities.

This is not the case with the Fergana Valley, which spans Tajikistan, Kyrgyzstan and Uzbekistan. An impoverished hotbed of Islamism and drug trafficking, it may become a major source of terrorism and instability, especially after 2014, when American troops leave Afghanistan. This is where the Islamic Movement of Uzbekistan is active, the organization Kurbanov is accused of belonging to, aiding and abetting.

U.S. counterintelligence, antiterrorism and law-enforcement communities should increase their skill base to deal with the Eurasian Muslim diasporas. This includes knowledge of their history, geography, religion and politics. It also means hiring more American citizens who are native or near-native speakers of key Eurasian languages for counterterrorism jobs—subject to appropriate screening. We should also improve the tracking of travelers to Eurasia’s unstable zones such as the North Caucasus and Fergana Valley.

There is no substitute for prevention. The FBI should expand its work with Eurasian Muslim communities in the U.S. to counter radical propaganda and improve early identification of potential extremists. Finally, the U.S. should expand cooperation with security services in Europe and Eurasia, while keeping in mind that, for political reasons, authoritarian regimes may sometimes falsely accuse opposition figures of extremism.

We must not paint entire Eurasian Muslim communities with the brush of suspicion, but violent Islamism clearly is beginning to sink its poisonous roots among these groups. More vigilance and better preventive intelligence work, together with a deeper understanding of the respective regions’ ethnicity, religion, geography and politics, can go a long way to prevent a repetition of Boston-style attacks.

Ariel Cohen, Ph.D., is senior research fellow in Russian and Eurasian Studies and International Energy Policy at the Heritage Foundation.