The imperial boomerang is the thesis that governments that develop repressive techniques to control colonial territories will eventually deploy those same techniques domestically against their own citizens. This concept originates with Aimé Césaire in Discourse on Colonialism (1950) where it is called the terrific boomerang to explain the origins of European fascism in the first half of the 20th century. Hannah Arendt agreed with this usage, calling it the boomerang effect in The Origins of Totalitarianism (1951). According to both writers, the methods of Adolf Hitler and the Nazi Party were not exceptional from a world-wide view because European colonial empires had been killing millions of people worldwide as part of the process of colonization for a very long time. Rather, they were exceptional in that they were applied to Europeans within Europe, rather than to colonized populations in the Global South. It is sometimes called Foucault's boomerang even though Michel Foucault did not originate the term.