From the preface:
"The 1966 'Human Factors' edition focused on the contemporary threat of Maoist insurgencies, particularly in Southeast Asia, and also drew extensively on World War II resistance movements in Europe. Much of this information is still relevant and has been retained and integrated.
In the post-Cold War world, the most important insurgencies tend to be ethnic and religious. Long-simmering conflicts, sometimes with roots in colonial policies, have become prominent; examples include the Liberation Tigers of Tamil Eelam (LTTE) in Sri Lanka, Euskadi Ta Askatasuna (Basque Homeland and Freedom or ETA) in Spain, the Hutu-Tutsi genocides, the Ushtia lirimtare e Kosovs (Kosovo Liberation Army, or KLA), and the Provisional Irish Republican Army (PIRA). Battle lines in these conflicts are often drawn along ethnic lines, even when land or politics are the immediate issues in contention.
The other important new category is extremist religious movements, most prominently Islamic groups, including regional insurgent movements like Hizbollah and Harakat al-Muqawamah al'Isla miyyah (Islamic Resistance Movement, or HAMAS) and global movements like Al Qaeda. These present a different profile of ideology, organizational forms, and psychology than either Cold War Maoists or post-colonial ethnic insurgencies (although the Palestinian cause could be considered a post-colonial issue).
Globalization has also changed underground operations in numerous ways. Insurgencies, enabled by low-cost transportation, Internet based communications, and other information technologies, can more easily recruit, communicate, and operate across borders. It is correspondingly much more difficult to contain an insurgency in a region. Global media has led to development of new tactics, in particular new types of terrorism, designed to capture worldwide attention.
Compared with what was available in the 1960s, there are orders of magnitude more academic research available relevant to this study's topics. We were able to draw on more recent work in psychology, political science, economics, sociology, organizational studies, and communications studies.
Readers of this edition will, over the course of eleven chapters, get a wide exposure to basic concepts from a number of disciplines".