National activities to protect the natural environment ave on the rise. Conventional explanations of the phenomenon emphasize domestic processes, set in motion by environmental degradation and economic affluence. We propose instead a top-down causal imagery that hinges an a global redefinition of the "nation-state" to include environmental protection as a basic stare responsibility. We test our view using event-history analyses of five indicators Of environmentalization. the proliferation of (I) national parks, (2) chapters of international environmental associations, (3) memberships in intergovernmental environmental organizations, (4) environmental impact assessment laws, and (5) environmental ministries in countries around the would over the twentieth century For all five measures, the top-down global explanation proves stronger than the bottom-up domestic alternative: The global institutionalization of the principle that nation-states beau responsibility for environmental protection drives national activities to protect the environment. This is especially true in countries with dense ties to world society and prolific "receptor sites," even when controlling for domestic degradation and affluence It appears that blueprints of nation-state environmentalization, which themselves become more universalistic over time, are drawn in world society before being diffused to and enacted by individual countries.
