In 1870, the Italian physician Cesare Lombroso examined the skull of a dead thief named Giuseppe Villella and decided he had found the source of criminality. Villella’s skull carried a small depression that Lombroso compared to the skulls of apes and early humans, and from that single observation he built a theory that shaped criminology for decades.
According to the theory, criminals were not people who made choices; they were biological throwbacks, identifiable by jaw size, ear shape and facial asymmetry. Lombroso called it atavism.
Governments and courts took it seriously enough to let physiognomy influence verdicts, and a version of the same logic later crept into how societies explained political violence, pointing to race, ethnicity, religion or inherited pathology as the hidden engine behind the man who kills for a cause.
That engine turned out to be imaginary. What actually drives a person to plant a bomb or hijack a train has never been written on a face or coded into a bloodline. It is written increasingly in a search for someone to be.
Terrorism is a form of irregular warfare. It rejects the uniformed, state-versus-state model that defines conventional conflict and instead uses small, mobile, deniable violence against a stronger opponent, aiming to generate fear, media attention and political pressure that outweighs the group’s actual size.
A single attack can do more work than an army division, which is precisely the appeal to actors who cannot win a direct fight. Governments have designated groups like the Tehrik-e-Taliban Pakistan and the Balochistan Liberation Army as foreign terrorist organizations because their methods sit outside the laws of armed conflict, even where their stated grievances resemble those of any insurgency.
The late scholar David Rapoport gave the clearest account of how this kind of violence evolved, describing four successive waves of modern terrorism since the 1880s. The first, the Anarchist wave, ran from roughly 1879 to the 1920s and produced assassins who saw themselves as agents of an inevitable revolution against monarchy and bourgeois order.
The second, the Anti-Colonial wave, spanned the 1920s to the 1960s, as groups like the Irish Republican Army and Algeria’s National Liberation Front fought to expel colonial powers.
The third, the New Left wave, ran through the 1960s to the 1990s and produced hijackings and hostage-taking in the name of anti-capitalist revolution. The fourth, the Religious wave, began in 1979 and gave the world suicide bombing as a tactic, largely, though not only, within groups that framed their violence in Islamic terms.
Each wave had a different language of justification, but Rapoport’s own framework treats that language as an “energy,” a mobilizing narrative rather than a fixed cause. Narratives change. What replaces them in the 21st century looks less like ideology and more like a transaction.
The psychologist Arie Kruglanski built a body of research, significance quest theory, around exactly this shift. His model argues that violent extremism is driven above all by a need for personal significance — the desire to matter and to be respected — and that ideology functions mainly as the narrative that tells a person which violent acts will restore that significance.
Unemployment and social alienation are consistently identified in follow-up research as triggers for the quest, because joblessness strips a person of status and belonging at the same time.
A separate 2010 study for the US Institute of Peace on why youth join al-Qaida found something similar from another angle. The recruits studied did not fit a clean economic profile — some were poor, some were not — but what tied them together was a set of needs the group describes as revenge, status, identity and thrill: in other words, significance. Money and rank inside a militant hierarchy have become one of the more reliable ways to buy that significance.
Tehrik-e-Taliban Pakistan (TTP) offers a clear illustration. Formed in 2007 under Baitullah Mehsud, the group has always financed itself through donations, extortion, kidnappings and the sale of natural resources in the tribal districts along the Afghan border — a business model as much as a battle plan.
In 2024, Pakistan’s government renamed the group Fitna al-Khawarij, an attempt to reframe the TTP as a deviant sect rather than a legitimate religious insurgency. The group’s response, chronicled in reporting on its rebranding, has been to lean harder into Pashtun nationalist grievance instead of global jihadist rhetoric, swapping one narrative for another as its audience and funding needs shift. Recent recruitment tells the same story.
A 2025 Bangladeshi investigation into a TTP pipeline recruiting young men from Dhaka and Madaripur found recruits who came from modest households — a rickshaw driver’s son, an electrical laborer’s son — drawn in through online forums that a Bangladeshi aeronautical engineer used to run, according to reporting from Durand Dispatch. These are not scholars of theology. They are young men offered a wage, a rifle and a sense of purpose.
Al-Qaida’s own history undercuts the idea that religious conviction alone explains its recruits. Researchers examining the group’s financing in the West found that most of its support cases involved a few thousand US dollars moved through unsophisticated channels by ordinary supporters, not a well-funded ideological machine but a patchwork of small transactions, according to a George Washington University study of the group’s American networks.
The same USIP interviews turned up something just as telling on the recruitment side: clinical mental illness was almost entirely absent, and a purely economic profile did not fit either, but the common denominator was a hunger for relevance in a life that otherwise offered none. Al-Qaida gave that hunger a uniform and a rank structure, which is a currency of its own.
Sri Lanka’s Liberation Tigers of Tamil Eelam ran an even more explicit criminal enterprise behind its nationalist banner. Founder Velupillai Prabhakaran came out of Jaffna’s black market gangs, not a seminary or a university faculty.
The group he built later ran extortion rackets across the Tamil diaspora in Canada, Britain, the United States and Australia, documented in a Human Rights Watch investigation. Diaspora contributions, willing and coerced alike, are estimated to have supplied as much as four-fifths of the group’s annual budget.
Families in Toronto were told to pay a set fee or lose the ability to visit relatives back home. Heroin trafficking supplemented the diaspora tax, a detail confirmed by the Mackenzie Institute’s analysis of the group’s early leadership, which traces the LTTE’s financial machinery directly to Prabhakaran’s pre-insurgency criminal contacts. Tamil nationalism supplied the banner; extortion and narcotics supplied the operating budget; and status within the organization supplied the motive for the people who ran it.
Balochistan’s insurgency shows the same pattern playing out in real time. The Balochistan Liberation Army, designated a foreign terrorist organization by Washington in 2025, has grown from roughly 500 fighters in the mid-2010s to a claimed 5,000 to 6,000 today, according to Jamestown’s Terrorism Monitor. Researchers tracking the group describe its evolution from a tribal, Marri-and-Bugti-led guerrilla force into a “middle-class insurgency” drawing on educated youth and women.
Revenue from Balochistan’s coal mines has become a central source of funding, an Al Jazeera analysis of the group’s finances found, alongside American-made weapons that flowed across the porous Afghan border after the 2021 withdrawal. Baloch nationalism explains why the group exists. It does not fully explain why its ranks have grown roughly tenfold in a decade. Money and rank have been used to recruit them.
None of this means ideology has disappeared from the vocabulary of these organizations. Every group discussed here still speaks in the language of faith, ethnicity or national liberation, and every one of their recruiters still leads with that language because it is what makes the offer sound noble rather than transactional. However, the language is the wrapping, not the contents.
Strip away the sermon and the flag, and what remains in each case is a young man who wanted to matter, an economy that could not offer him that, and an organization willing to pay him — in cash, rank or attention. Lombroso was wrong to look for the terrorist in a skull.
The 21st-century terrorist is not encoded into any bloodline or creed. Rather, he or she is born into an economy where violence has simply become the most reliable currency and the best-paid vocation.
Farwa Imtiaz is an independent academic researcher with a Master’s degree in Peace and Conflict Studies from National Defence University, Pakistan. Her work has been featured in The Friday Times, Paradigm Shift, South Asia Times, Voice of Germany, Global Connectivities, Stratheia, EcoAsiaNews, International Policy Journal, South Asia
Journal, Sri Lanka Guardian, Global South Forum, and Middle East Monitor.
