Several attempts at using the Services Oriented Architecture have failed to achieve their goals of scalability, security, and manageability. These systems, which base access decisions on the identity of the requester, have been found to be inflexible, don?t scale well, and are difficult to use and to upgrade. This paper shows that identity-based access control is a key contributor to these failures and proposes another way to approach the problem. Basing access control decisions on authorizations presented explicitly by the requester leads to a more securable and more robust architecture.