Terrorism is an ancient political tactic that has continually evolved with society—from daggers to dynamite, from hijacked airplanes to social media—while retaining one central objective: using fear to influence human behavior.
And that is why understanding the history of terrorism matters.
To understand terrorism today, we have to understand where it came from, how it evolved, and why it continues to work.
A HISTORY OF TERRORISM
THE LONG HISTORY OF USING FEAR AS A WEAPON
Terrorism may sound like a modern phenomenon.
It isn’t.
People have used violence, intimidation, assassination, and fear to influence governments and populations for thousands of years.
What has changed is the technology, organization, ideology, reach, and objectives of those who use terror.
The history of terrorism is therefore not simply a history of bombs and guns.
It is a history of power—and the struggle to obtain it, keep it, or destroy it.
1. BEFORE THE WORD “TERRORISM”
Long before anyone used the word terrorism, rulers and political movements understood a basic principle:
Fear can change behavior.
Ancient rulers sometimes used spectacular violence to discourage rebellion. Armies destroyed cities. Kings executed opponents publicly. Empires punished rebellious populations.
These acts were brutal, but we should be careful about automatically calling them “terrorism.”
Modern terrorism is a specific analytical and political concept. Ancient violence may resemble terrorism in some respects without fitting today’s definitions.
The important historical lesson is simpler:
2. THE SICARII: VIOLENCE IN ANCIENT JUDEA
One of the groups frequently discussed in histories of terrorism is the Sicarii, a Jewish resistance movement operating in Roman-controlled Judea during the first century CE.
The name is associated with the sica, a small dagger.
The Sicarii used assassination and intimidation against individuals they regarded as collaborators with Roman rule.
Their methods illustrate an important feature that would appear repeatedly throughout the history of terrorism:
The target of violence may be one person, but the intended audience can be much larger.
The assassination was not simply about the individual.
It could send a message to an entire community.
3. THE ASSASSINS
During the medieval period, another group became famous for political assassination: the Nizari Ismailis, commonly known in European history as the “Assassins.”
Operating primarily in parts of Persia and Syria, they developed a reputation for targeted killings of political and military figures.
Their historical importance lies partly in their use of selective violence.
They did not need to defeat an entire army.
They could attempt to influence political behavior by demonstrating that important individuals were vulnerable.
Again, the basic calculation was familiar:
A relatively small amount of violence can produce a much larger psychological effect.
4. THE FRENCH REVOLUTION: WHEN “TERROR” BECAME POLITICAL LANGUAGE
The modern word terrorism has its strongest historical roots in the French Revolution.
During the Reign of Terror, from 1793 to 1794, revolutionary authorities used executions, imprisonment, surveillance, and political repression against perceived enemies of the revolution.
This period is critical because terror became an explicit instrument of government policy.
The French term la Terreur referred to a political system in which fear was deliberately employed to defend and consolidate revolutionary power.
This produced an important historical development:
The word “terrorism” emerged from this political environment.
5. THE 19TH CENTURY: TERRORISM GOES UNDERGROUND
The nineteenth century produced a major transformation.
Political movements increasingly formed secret organizations and revolutionary cells.
Some believed existing governments were so corrupt or oppressive that violence was necessary to destroy them.
A particularly important movement was anarchist terrorism.
Anarchist militants attacked political leaders, police, government officials, and other symbols of state authority in Europe, Russia, and elsewhere.
Their philosophy varied, but some believed that spectacular acts of violence could inspire popular revolt.
This became known as the strategy of:
“propaganda by the deed.”
The idea was simple:
Do something dramatic, and people will pay attention.
6. ASSASSINATION AS A POLITICAL WEAPON
The late nineteenth and early twentieth centuries saw numerous political assassinations.
Political leaders became targets because killing one individual could create enormous political consequences.
The assassination of Archduke Franz Ferdinand of Austria-Hungary in 1914 by Gavrilo Princip is a famous example.
The assassination itself was carried out by an individual associated with a Serbian nationalist revolutionary network.
Its consequences were enormous.
It helped trigger the chain of events leading to World War I.
This demonstrated another characteristic of political violence:
7. NATIONALISM AND ANTI-COLONIAL VIOLENCE
During the twentieth century, terrorism increasingly became connected with national liberation and anti-colonial movements.
Groups fighting colonial governments sometimes used:
Assassination
Bombings
Kidnapping
Sabotage
Guerrilla warfare
Attacks on government personnel
Attacks on civilians
Some movements viewed themselves as freedom fighters.
Their governments viewed them as terrorists.
This created—and continues to create—a major problem in terrorism analysis:
The same organization can be described very differently depending on who is doing the describing.
That is why Terrorism Report must distinguish between:
what a group calls itself,
what its opponents call it,
and
what the evidence demonstrates.
8. THE AGE OF THE AIRPLANE
Technology changed terrorism.
Commercial aviation created something terrorists had never possessed before:
global mobility and global publicity.
By the 1960s and 1970s, hijacking aircraft became an increasingly prominent terrorist tactic.
An airplane could be seized in one country and transported to another.
Television could then broadcast the crisis around the world.
The terrorist act had acquired a new weapon:
the global audience.
The objective was no longer simply to attack.
It was to make sure everyone saw the attack.
9. THE 1970s: TERRORISM BECOMES INTERNATIONAL
The 1970s marked a major expansion of international terrorism.
Organizations from different ideological backgrounds carried out attacks across national borders.
These included:
Palestinian militant organizations
Left-wing revolutionary groups
Separatist movements
Nationalist organizations
Far-right groups
Other extremist organizations
Kidnappings, airline hijackings, hostage-taking, assassinations, and bombings became international news.
Governments began creating specialized counterterrorism organizations.
International cooperation became increasingly important.
Terrorism was no longer simply a domestic security problem.
It had become an international problem.
10. RELIGIOUS EXTREMISM AND THE NEW TERRORISM
During the late twentieth century, religiously motivated terrorism became increasingly prominent.
Organizations associated with militant interpretations of Islam became particularly significant.
The 1979 Iranian Revolution, the Soviet invasion of Afghanistan, the Afghan jihad, and subsequent conflicts helped create political and military environments in which transnational Islamist militant networks developed.
Organizations such as al-Qaeda eventually developed a global strategy.
This represented another important transformation.
The terrorist organization was no longer necessarily focused on one government or one territory.
It could have:
International recruits
International financing
Training camps
Cells in multiple countries
Global communications
Transnational leadership
The organization itself became global.
11. SEPTEMBER 11, 2001
The attacks of September 11, 2001, fundamentally changed the modern history of terrorism.
Al-Qaeda hijackers seized four commercial aircraft.
Two were flown into the World Trade Center towers in New York.
One struck the Pentagon.
A fourth crashed in Pennsylvania after passengers attempted to regain control of the aircraft.
Nearly 3,000 people were killed.
The attacks demonstrated the potential consequences of combining:
ideological motivation + organizational planning + modern transportation + mass communication + asymmetric tactics.
The response transformed international security policy.
The United States launched the War on Terror.
Countries around the world expanded counterterrorism laws, intelligence cooperation, airport security, financial surveillance, and military operations.
12. THE INTERNET CHANGES EVERYTHING
The next revolution was digital.
Terrorist organizations discovered that they no longer needed television networks to reach an international audience.
They had the internet.
Websites, online forums, social media, encrypted communications, videos, magazines, and messaging applications transformed terrorist propaganda.
The internet became useful for:
Recruitment
Propaganda
Fundraising
Communications
Radicalization
Psychological warfare
Claiming responsibility
Distributing ideological material
The terrorist organization had acquired something previous generations could only dream about:
a worldwide communications system that could reach potential supporters directly.
13. ISIS AND THE DIGITAL CALIPHATE
The rise of ISIS, also known as the Islamic State, demonstrated the power of this new environment.
ISIS combined territorial warfare with sophisticated propaganda.
At its height, it controlled significant territory in Iraq and Syria while simultaneously conducting or inspiring attacks beyond the region.
It recruited internationally.
It produced highly sophisticated propaganda.
It encouraged supporters abroad to conduct attacks even when they could not travel to territory controlled by the organization.
This created a new model:
The terrorist organization did not always have to send the attacker.
It could inspire someone thousands of miles away to act.
14. LONE ACTORS AND SELF-RADICALIZATION
Modern terrorism increasingly includes attacks carried out by individuals with limited or no direct organizational connection.
These individuals are sometimes described as:
Lone actors
Lone offenders
Self-radicalized extremists
Inspired attackers
The internet can allow individuals to consume extremist propaganda without ever meeting members of the organization producing it.
This creates a difficult problem for governments.
A traditional terrorist organization leaves organizational footprints.
A lone actor may leave very few.
15. FAR-RIGHT AND OTHER FORMS OF EXTREMIST VIOLENCE
Modern terrorism is not exclusively associated with Islamist organizations.
Far-right, white supremacist, anti-government, separatist, revolutionary, and other extremist movements have also employed terrorism or terrorist tactics.
The motivations differ.
The underlying principle can be similar:
Use violence to frighten people and influence political or social behavior.
This is why a serious terrorism publication should avoid treating terrorism as synonymous with any single religion, ethnicity, nationality, or political ideology.
Terrorism is a method of political violence.
Different ideologies can employ it.
16. TERRORISM TODAY
Modern terrorism is increasingly decentralized.
Some organizations maintain traditional command structures.
Others operate through loose networks.
Some control territory.
Others operate underground.
Some have sophisticated financial systems.
Others depend on donations, criminal activity, state support, or informal financing.
Some recruit thousands.
Others inspire a handful of individuals.
And some individuals act almost entirely on their own.
Technology continues to change the battlefield.
Today’s terrorist organizations can potentially exploit:
Social media
Encrypted communications
Drones
Cyber capabilities
Cryptocurrency and digital finance
Artificial intelligence
Online recruitment
Global transportation
Mass media
The tools change.
The underlying objective often remains familiar:
17. WHAT HAS CHANGED?
The history of terrorism can be understood as a series of technological and organizational revolutions.
ANCIENT WORLD
Fear was primarily local.
MEDIEVAL PERIOD
Targeted political assassination demonstrated the power of selective violence.
FRENCH REVOLUTION
“Terror” became an explicit political instrument.
19TH CENTURY
Secret revolutionary organizations used assassination and violence to spread political messages.
20TH CENTURY
Nationalist, revolutionary, separatist, and anti-colonial organizations expanded terrorism’s reach.
1970s
International terrorism and mass media became increasingly connected.
2001
9/11 demonstrated the potential scale of transnational terrorism.
2000s–2010s
The internet transformed propaganda and recruitment.
TODAY
Terrorism is increasingly networked, decentralized, international, and technologically sophisticated.
18. THE CONSTANT
After thousands of years, one principle remains remarkably consistent:
Terrorism is about more than the immediate victim.
The person who is killed may be the target.
But the people watching may be the real audience.
The government may be the real target.
The community may be the real target.
The organization may be trying to recruit.
The movement may be trying to demonstrate strength.
Or the attacker may simply want the world to pay attention.
That is the fundamental logic of terrorism:
THE HISTORY OF TERRORISM IN ONE SENTENCE
Terrorism is an ancient political tactic that has continually evolved with society—from daggers to dynamite, from hijacked airplanes to social media—while retaining one central objective: using fear to influence human behavior.
And that is why understanding the history of terrorism matters.
To understand terrorism today, we have to understand where it came from, how it evolved, and why it continues to work.