Policy management system with proactive and reactive monitoring and enforcement

Some embodiments provide a method for a system that monitors a network to prevent violations of network policies. The method stores network state data that describes the network. The method identifies that a first set of stored network state data violates a particular policy declared for the network. The method issues a command to a first cloud management application to modify the network state data such that the modified network state data does not violate the particular policy. The method determines whether a requested action that modifies a second set of network state data, received from a second cloud management application, violates any policies. The method responds to the second cloud management application to permit the requested change when the modified second set of network state data does not violate any policies and deny the requested change when the modified second set of network state data violates the particular policy.