In the mid-1970s, French, German, and Swiss protesters jointly occupied the Wyhl nuclear reactor construction site in the Upper Rhine Valley. Even at the grassroots level, transnational cooperation allowed reactor opponents to transcend the limits of politics-as-usual and adopt “new” protest strategies. Moreover, though it was minutely local, the Wyhl occupation had significant transnational effects. Activists throughout Europe and even across the Atlantic considered this protest to influence the situation in their home countries. They were eager to build on the “example of Wyhl.” Yet, as this article shows, activists beyond the Rhine had a hard time deploying transnationalism in the mass anti-nuclear protests and political campaigns that followed Wyhl. The West German Greens’ 1979 European Parliament campaign is perhaps the best example of the way that activists inspired by Rhenish protests continued to emphasize transnationalism. Despite their European outlook, however, the Greens’ first major political success came in Bonn, not Strasbourg. Thus, for the Greens and many others transnational thinking proved difficult to sustain beyond the grassroots level. It may have been most effective as a means of reinvigorating national politics.