The Internet is currently evolving beyond what its architecture can support. Often, the mechanisms that allow the Internet to adapt to increasingly conflicting sets of new requirements break some of its basic design principles and can thus severely interfere with end-to-end communication. This paper recognizes that increased autonomy of network regions is a key requirement for future internetworking. It outlines a new internetworking architecture that enables interoperation among a set of autonomous, heterogeneous network domains. The architecture is based on a global identity space and does not require global addressing or a shared internetworking protocol. It integrates the new concept of dynamic network composition with other recent architectural concepts, such as decoupling locators from identifiers.