1. A method of enforcing a policy on a client device, comprising: receiving, in a client device, a policy definition from a network, wherein the policy definition is a generic definition that is applicable to disparate device types having different hardware and software platforms; evaluating the received policy definition in a client policy engine located on the client device by comparing the policy definition to use or functionality available on the client device; and enforcing the policy by modifying the functionality available on the client device based on the evaluation, wherein the client policy engine adapts the generic policy definition to a specific platform on the client device.