Communities of practice (CoPs) are important sites of social interaction and are of growing concern in international relations. Much attention has been devoted to examining the existence and effect of these communities, and the kinds of practices and identities they coalesce around. Relatively less attention has been afforded to the relations between a CoP and what lies outside of it. In this article we examine encounters at the boundaries of CoPs. Empirically, we examine the boundaries and interactions of a community of diplomatic practice in the context of the...… Communities of practice (CoPs) are important sites of social interaction and are of growing concern in international relations. Much attention has been devoted to examining the existence and effect of these communities, and the kinds of practices and identities they coalesce around. Relatively less attention has been afforded to the relations between a CoP and what lies outside of it. In this article we examine encounters at the boundaries of CoPs. Empirically, we examine the boundaries and interactions of a community of diplomatic practice in the context of the...WW…