Recent cybersecurity events have prompted the federal government to begin investigating strategies to transition to Zero Trust Architectures (ZTA) for federal information systems. Within federated mission networks, ZTA provides measures to minimize the potential for unauthorized release and disclosure of information outside bilateral and multilateral agreements. When federating with mission partners, there are potential risks that may undermine the benefits of Zero Trust. This paper explores risks associated with integrating multiple identity models and proposes two potential avenues to investigate in order to mitigate these risks.