Activism, in a general sense, can be described as involvement in action to bring about change, be it social, political, environmental, or other change. This action is in support of or opposition to one side of a controversial argument.
There are many different forms of activism; a select list follows.
... Pierre Brossolette in Paris.
Comité Départemental de Libération[?] (CDL or Departmental Liberation Committee)
Comité Français de la Libération Nationale[?] ...