We consider noncoercive means for harnessing the efforts of the private sector as partners with public authorities for addressing potential harms from widely dispersed risks. Our focus is the public and private sector approach in the United States to protecting the nation's critical infrastructures. We empirically address how two key elements of this approach—mobilization of attention and planning partnerships—work to foster “communities of interest” that pursue common sets of solutions for risk reduction. Our depiction of the varied communities of interest underscores differences in starting points in creating such communities, in the ability to mobilize and focus attention within them, and in the likelihood of sustaining efforts to address threats to critical infrastructures. The fundamental issue raised by our research is striking an appropriate balance between governmental and private sector roles in addressing risks for which it is hard to create and sustain protective actions.