1. A system for managing requests, the system comprising: a policy enforcement point, implemented on one or more servers, configured to intercept communications; a policy repository; one or more security servers configured to: receive requests for authorization from the policy enforcement point; retrieve, from the policy repository, a dynamically-loadable security access policy associated with one or more protected resources, wherein the dynamically-loadable security access policy comprises one or more rules; determine at least one attribute required by at least one of the rules of the dynamically-loadable security access policy retrieved from the policy repository and associated with the one or more protected resources: for at least one of the attributes required by a rule of the dynamically-loadable security access policy retrieved from the policy repository and associated with the one or more protected resources, determine whether an attribute value must be requested; request at least one of the attribute values that must be requested from a remote data source; retrieve from the remote data source the at least one of the attribute values: evaluate the security access policy retrieved from the policy repository and associated with the one or more protected resources using the at least one of the attribute values from the remote data source; and return an authorization decision to the policy enforcement point.