Guerrilla warfare is a form of irregular warfare and refers to conflicts in which a small group of combatants including, but not limited to, armed civilians (or "irregulars") use military tactics, such as ambushes, sabotage, raids, the element of surprise, and extraordinary mobility to harass a larger and less-mobile traditional army, or strike a vulnerable target, and withdraw almost immediately.

The term means "little war" in Spanish, and the word, guerrilla, has been used to describe the concept since the 18th century, and perhaps earlier. A person who is a member of a guerrilla is a guerrillero.

The term 'guerrilla' was used within the English language as early as 1809. The word was used to describe the fighters, and their tactics (e.g."the town was taken by the guerrillas"). However, in most languages guerrilla still denotes the specific style of warfare. The use of the diminutive evokes the differences in number, scale, and scope between the guerrilla army and the formal, professional army of the state.

Max Boot (born September 12, 1969) is an American author, consultant, editorialist, lecturer, and military historian. He has been a prominent advocate for American power. He once described his ideas as "American might to promote American ideals." He self-identifies as a conservative, once joking that "I grew up in the 1980s, when conservatism was cool". Boot worked as a writer and editor for Christian Science Monitor and then for The Wall Street Journal in the 1990s. He is now Jeane J. Kirkpatrick Senior Fellow in National Security Studies at the Council on Foreign Relations. He has written for numerous publications such as The Weekly Standard, The Los Angeles Times, and The New York Times and he has also authored well-reviewed books of military history.

Boot was born in Moscow. His parents, both Russian Jews, later emigrated from the Soviet Union to Los Angeles, where he was raised. Boot earned a Bachelor's Degree in History from the University of California, Berkeley in 1991, and a Master's Degree in Diplomatic History from Yale University in 1992. He started his journalistic career writing columns for the Berkeley student newspaper The Daily Californian. Boot and his family currently live in the New York area.

Ahmad Shah Massoud (احمد شاه مسعود Aḥmad Šāh Mas'ūd; September 2, 1953 – September 9, 2001) was a political and military leader in Afghanistan. He was a central figure, known as the "Lion of Panjshir", in the resistance against the Soviet occupation between 1979 and 1989, fought against the alliance of Gulbuddin Hekmatyar in the early 1990s, and led resistance against the Taliban regime between 1996 and 2001. Massoud was assassinated on September 9, 2001, two days before the attacks of September 11.

Massoud was an Afghan-Tajik Sunni Muslim born in the Panjshir in northern Afghanistan. He studied engineering at Kabul University in the 1970s, where he became involved with Muslim anti-communist movements around Burhanuddin Rabbani. He led an uprising against the Soviet-backed communist government in his native Panjshir in 1979. His role in the following period of armed resistance against the Soviet occupation forces earned him the nickname of "Lion of Panjshir" (شیر پنجشیر). Following the withdrawal of Soviet troops from Afghanistan the Wall Street Journal named Massoud "the Afghan who won the Cold War". In 1992, he was appointed minister of defense in the government of the newly established Islamic State of Afghanistan by the peace and power-sharing agreement Peshawar Accords. He led the Islamic State's defense against attacks by Gulbuddin Hekmatyar's alliance of militias which were backed by Pakistan. Following the rise of the Taliban in 1996, Massoud, who rejected the Taliban's and Al-Qaeda's extremist interpretation of Islam, returned to the role of an armed opposition leader, serving as the military and political leader of the multiethnic United Islamic Front (also known in the West as Northern Alliance). In 1997, he helped end the civil war in neighboring Tajikistan urging parties to accept a United Nations peace plan.