revisionism (n.)

1903, from revision + -ism. Originally in reference to a policy of introducing socialism gradually, by evolution rather than revolution, used as a term of abuse by Marxists. The general sense of "revised attitude toward some situation, doctrine, etc." is by 1921. Revisionist (adj.) "favoring or supporting revision" (of a creed, law, etc.) is from 1850; as a noun from 1854 in reference to one who favors or supports revision; specifically in reference to historical narratives by 1934, originally of the causes of World War I.