A resistance movement is a group or collection of individual groups, dedicated to fighting an invader in an occupied country or the government of a sovereign nation through either the use of physical force, or nonviolence. The term resistance has political overtones, as people have used it, along with similar terms, to bring support to opposition groups.
Organizations and individuals critical of foreign intervention and supporting forms of organized movement (particularly where citizens are affected) tend to favor the term. When such a resistance movement uses violence, those favorably disposed to it may also speak of freedom fighters. Both phrases -- resistance movement and freedom fighters -- can become contentious terms for what other observers might describe as terrorists, though this is controversial as terrorists are often criticized and seen as morally wrong, whereas many see Resistance Movements as legitimate. The popular saying "One person's terrorist is another person's freedom fighter" encapsulates this dichotomy, without clarifying the distinction that freedom fighters must, by definition, be fighting for freedom. Terrorists, as a modern appellation, are not seen as fighting for freedom, whereas Resistance Movements are. Thus, Resistance Movements may employ terror tactics, but not all who use terror tactics are called a Resistance movement.
Tactics of resistance movements against a constituted authority range from nonviolent resistance and civil disobedience, to industrial sabotage and guerrilla warfare, or even conventional warfare if the resistance movement is strong enough. Any government facing violent acts from a resistance movement usually condemns such acts as terrorism, even when such attacks target only the military or security forces.
Resistance during World War II was dedicated to fighting the Axis invaders. Germany itself also had an anti-Nazi German resistance movement in this period. Although mainland Britain did not suffer invasion in World War II, the British made preparations for a British resistance movement in the event of a German invasion.
In strict military terminology, a resistance movement is simply that; it seeks to resist (change) the policies of a government or occupying power. This may be accomplished though violent or non-violent means. A resistance movement is specifically limited to changing the nature of current power, not to overthrow it. The correct military term for removing or overthrowing a government is an insurgency.
Planned resistance movements: