Department of the Army - U.S. Army Guerrilla Warfare Handbook

a. General. Resistance is the cornerstone of guerrilla warfare. Underground and guerrilla warfare stem from a resistance movement.

b. Definition. Resistance is defined as the act of opposition of one individual or group to another. A resistance movement is the organized element of a disaffected population which resists a government or occupying power with means varying from passive to violently active. Resistance movements begin to form when dissatisfaction occurs among strongly motivated individuals who cannot further their cause by peaceful and legal means.

c. The Nature of Resistance .

1. Resistance, rebellion or civil war begins in a nation where political, sociological, economic or religious division has occurred. Divisions of this nature are usually caused by a violation of rights or privileges, the oppression of one group by the dominant or occupying force, or the threat to the life and freedom of the populace. Resistance also may develop in a nation where the once welcomed liberators have failed to improve an intolerable social or economic situation. Resistance can also be deliberately inspired from external sources against an assumed grievance. Resistance can be active or passive. Passive resistance may be in the form of smoldering resentment which needs only leadership or a means of expression to mature to active resistance.
2. Some people join a resistance movement because of an innate desire to survive. Others may join the resistance forces because of deep ideological convictions. But all, regardless of initial motivation, are bound together to fight against a common enemy. Part of the population assists the resistance movement as fighters in the guerrilla force; some assist as part-time guerrillas or in civilian support agencies know as auxiliary units; while others are members of the underground.

d. Influencing Factors .

1. Environment.
   • ( a ) Terrain. The physical location of the resistance movement has a great influence upon its organization and tactics. Because they provide suitable areas for the security of operations, mountains, swamps, large forests or jungles nurture overt or guerrilla type resistance. Flat plains areas and large towns or cities are more apt to lead to underground resistance activities although the possibility of organizing a guerrilla force in these areas should not be overlooked.
   • ( b ) Cultural. A peoples cultural environment also has its effects on resistance movements. The urge to bear arms, escape, and fight the enemy is dependent on the cultural background of the people. Men from rural or peasant environment, not subjected to tight governmental control, have more opportunity to show their hatred of the enemy occupation by overt and violent means such as guerrilla warfare. People from an industrialized and highly urbanized culture will resist with such activities as sabotage, propaganda, passive acts and espionage.
   • ( c ) Control of population . When an occupying power is able to exercise close and stringent control over the population, the resistance movement is conducted primarily in secrecy. When the police and military forces of the occupying power are diverted or otherwise ineffectual, the resistance movement may be conducted with primarily overt guerrilla actions.
2. Motivation . Besides the geographical and cultural environment influencing guerrilla warfare, the sociological climate produces many motivating factors which have a profound effect upon the resistance movement. Strong individual motivation is essential to the formation of a resistance force. Although some individual motives are not ideal and, if openly expressed, may do harm to the guerrilla effort, the following are examples of what some of the true motives may be.