 Marxist theorists including Rosa Luxemburg, Karl Kautsky, and Nikolai Bukharin also explored the issue of imperialism. Kautsky’s position is especially important because his analysis introduced concepts that continue to play a prominent role in contemporary world systems theory and post-colonial studies. Kautsky challenges the assumption that imperialism would lead to the development of the areas subjected to economic exploitation. He suggests that imperialism is a relatively permanent relationship structuring the interactions between two types of countries. (Young 2001) Although imperialism initially took the form of military competition between capitalist countries, it would result in collusion between capitalist interests to maintain a stable system of exploitation of the non-developed world. The most influential contemporary proponent of this view is Immanuel Wallerstein, who is known for world-systems theory. According to this theory, the world-system is a relatively stable set of relations between core and peripheral states. This international division of labor is structured to benefit the core states (Wallerstein 1974–1989) and transfers resources from the periphery to the core.