Police agencies nationwide have enhanced their homeland security preparedness capacity since the 9/11 attacks. Evidence suggests that departments have not uniformly adopted measures to prepare for and respond to critical incidents. Rather, larger agencies are more likely than their smaller peers to take such steps. Small agencies do not constitute a homogenous group; some experience geographic isolation while others are near major metropolitan areas. Unclear is whether small agencies (25 or fewer full-time sworn personnel), those that are commonly found to be less prepared, benefit from proximity to large-agency peers. This study examined whether physical and relational proximity to large departments contributed to homeland security preparedness in over 300 small departments. A structural equation model revealed that interactions with large agencies facilitated preparedness but physical proximity had no direct effect. Increasing geographic isolation from large-agency peers indirectly affected preparedness by stifling the level of inter-department interactions. Abstract published by arrangement with Taylor and Francis.