Data communication in the Internet is based on the borderless interplay of Autonomous Systems (ASes). An AS abstracts one or multiple IP networks, which may be globally distributed, but is owned by an organization located in a country. Current research on the Internet structure mainly focuses on a global perspective or considers local, intra-domain properties. In this paper, we analyze nation-centric subsets of the Internet taken from the AS-level graph of Germany. Each subset reflects a public or industrial sector. Based on a classified set of relevant German ASes, we are able to perform detailed investigations of structural dependencies for the critical Internet infrastructure. We identify and visualize the importance of dedicated ASes within specific sectors, and quantify robustness of the communication communities. Our preliminary results indicate that members of sectoral groups tend to ovoid direct peering, but connect via a small group of common ISPs. This results in an enhanced dependence (betweenness) on selected hubs as compared to the characteristics of larger networks.