A focused exchange on policies and practices facilitating interoperability and shared use of data and compute resources between and among national and institutional research clouds and development of a community "declaration" of those guiding principles. Workshop participants will explore of a range of issues identified as warranting further and more detailed exploration, including: relative focus on policy vs. technical capabilities; dealing with the concerns about the loss of control and lock-in; data ownership/sovereignty and security; federation of identity management and protocols for access and authorized use (across multiple organizational and political jurisdictions); shared use and interoperability; and addressing the combination of cultural and technical barriers to effective collaboration. Follow up workshops are being planned for Europe and Asia.