Terrorism is certainly not new. In fact, it is deeply embedded in history. The Zealots, for example, were a Jewish sect that appeared in 6 CE and assassinated local government officials in an attempt to ignite uprisings and drive the Romans out of Palestine. The Middle East spawned the Assassins (1090–1275), Muslims who killed the political rivals of the potentate for whom they worked. Christian Europe also had its experience with terror during the 15th-century Spanish Inquisition that combined the forces of church and state in trials and the burning of accused witches—a phenomenon that even touched the New World, most notably at Salem, Massachusetts, where witches were hanged in the 1690s.

Historically, the vast majority of terrorism in traditional societies has been religiously inspired; indeed, terrorists often claimed they were carrying out the will of God. These historical examples are a good reminder that religiously inspired terrorism—a major contemporary concern—is certainly not new.

It was the French Revolution in 1789, however, that popularized the term terrorism. During this period, terrorism was associated with the state, as the guillotine was used to behead publicly those who were declared enemies of the state. In later years, even more highly developed forms of state terrorism were practiced in both the Stalinist Soviet Union and Nazi Germany in the 1930s and 1940s.

The “knock at the door” by state authorities, the use of show trials and executions, and purges of large numbers of people were used by these regimes to instill fear in domestic populations, thus assuring greater compliance with the dictates of the state. Such tactics also found their way into Saddam Hussein’s Iraq as well as other states and societies whether on the left or right, secular or religious.

The 19th century witnessed the rise of a secular or nonreligious terrorism on the part of groups that were opposed to particular governments. During the 1800s, both the creative and destructive effects of the scientific and industrial revolutions became obvious in Europe and North America. Great wealth was created, as was great poverty. The birth of the modern city forever changed the rural ways of life. Humanity grew more confident in its ability to master nature and to design and create the perfect society. Karl Marx (1820–1872) and other communists demonstrated such faith in their vision of a worker’s paradise established after the victory of the downtrodden classes over their capitalist oppressors.

Other leftists, however, were impatient with the slow unfolding of history and wished to hasten the revolutionary process. Collectively known as anarchists, they accomplished a number of terrorist spectaculars. In the 1890s alone, anarchist victims included the presidents of France and Italy, the kings of Portugal and Italy, the prime minister of Spain, and the empress of Austria. Anarchists also attempted to assassinate the German kaiser (emperor) and chancellor. What distinguished them from modern-day terrorists, however, is that their victims were almost always government officials, not innocent civilians.

The Russian anarchist group known as the People’s Will, for example, rarely placed bombs in public places and never kidnapped schoolchildren or shot people in the knee to cripple them for life.With the collapse of the major continental monarchies in Russia, Germany, and the Austro-Hungarian Empire following World War I (1914–1918), factional ethnic violence and terrorism came to the fore. Under the banner of national self-determination, terrorist violence was particularly pronounced in Eastern and Central Europe.

A somewhat similar process began to unfold in the so-called “developing world” during and especially after World War II. Having fought Nazi Germany, fascist Italy, and Japan in defense of freedom, Western European leaders found it difficult to answer nationalist leaders in the colonial world who asked why their countries should not also be free from outside control. European reluctance to end colonial rule led nationalist movements, often with a terrorist wing, to fight British, French, Belgian, and Portuguese domination.

By the 1960s European colonial rule was effectively ended in most areas of the globe.The Cold War between the United States and the Soviet Union and their respective allies and supporters, however, lent an ideological cast to much of the terrorism perpetrated from the late 1940s to the late 1980s. Despite the fact that Karl Marx himself believed terrorism to be self-defeating, Marxist-Leninist teachings on revolution helped to inspire and justify revolutionary movements throughout the world and justify, to such participants at least, their use of terrorism. These movements included the Red Army Faction in Germany, Red Brigades in Italy, 17 November in Greece, Revolutionary Armed Forces of Colombia, Shining Path of Peru, Japanese Red Army, and New People’s Army of the Philippines.

Particularly in Europe, terrorism became the basic strategy of the organization, meaning it was the defining signature of the group. In the developing world, however, terrorism was generally a tactic on the part of an insurgent organization, meaning it was simply one aspect of a larger revolutionary strategy that included paramilitary attacks on government forces, the liberation of territory, and the extensive use of propaganda. Throughout the Cold War, insurgent organizations often combined Marxism-Leninism with old-fashioned nationalist appeals. Indeed, all successful revolutions, including Lenin’s in Russia and Mao’s in China, have relied extensively on such appeals. With the end of the Cold War, however, most Russians acknowledged that their Marxist-Leninist vision for society was bankrupt.

Furthermore, despite its socialist pronouncements, China experienced an economic boom as the state encouraged the development of a free market. These policies on the part of the two states most closely associated with Marxist-Leninist ideas on international revolution caused a predictable crisis of confidence for revolutionary movements around the world. Some, like Shining Path, simply condemned Russia and China for backsliding, while others, like the New People’s Army, experienced bitter internal divisions that weakened them. Now lacking a transnational ideological justification for their violent campaigns, other groups such as the Kurdistan Workers Party (PKK) shifted their emphasis away from Marxist ideology to more nationalist appeals. Nationalism has always provided the dynamism of the various original Palestinian organizations associated with the Palestine Liberation Organization (PLO). Despite couching their agenda in Islamic terms, even organizations such as Hezbollah (Party of God) in Lebanon and Hamas in the Palestinian West Bank of the Jordan River and in the Gaza Strip are also fueled in part by nationalist sentiment.

Israel, despite its historical association with the region, is viewed as an outpost of Western interests and values. For some observers in the West, the ideological clash of democracy and communism during the Cold War has been replaced by the clash of Eastern and Western civilizations. If not a clash of civilizations, others see conflicts driven by inter-communal and cultural differences that divide peoples in many parts of the world. Russia, for example, has suffered from a number of deadly suicide bombings related to ongoing ethnic conflicts in the Caucasus region.