Collaborationism is
cooperation with enemy
forces against one's
country.
Stanley Hoffmann subdivided collaboration onto
involuntary (reluctant recognition of necessity) and
voluntary (an attempt of exploiting necessity).
According to him, collaborationism can be subdivied onto
servile and
ideological,
the former is a deliberate service to an enemy, whereas the latter is a deliberate advocacy of co-operation with the foreign force which is seen as a champion of some desirable domestic transformations.
In contrast, Bertram Gordon used the terms "collaborator" and "collaborationist" for non-ideological and ideological collaborations, respectively.
Legally, it may be considered as a form of
treason. Collaborationism may be associated with
criminal deeds in the service of the occupying
power, which may include
complicity with the occupying power in
murder,
persecutions,
pillage, and
economic exploitation or participation in a
puppet government.