Which service should be utilized to enforce access control policies for applications in Google Cloud?

The Identity-Aware Proxy (IAP) is specifically designed to enforce access control policies for applications hosted in Google Cloud. It provides robust authentication and authorization features by securing application access based on user identity and the context of their request, such as device security status and location.

With IAP, you can manage access to web applications and APIs without needing to modify the applications themselves. By integrating with Google Identity services, IAP ensures that only authorized users can access specific resources, thereby enhancing the security posture of the application. It allows administrators to define who can access what application, adding a layer of security that is particularly beneficial for applications requiring stringent access control measures.

Cloud Identity serves as an identity management platform but does not directly enforce application-specific access policies. Similarly, Access Context Manager is focused on creating and managing access contexts for Google Cloud resources, which helps in defining conditional access policies but does not govern application traffic directly in the same manner as IAP. Lastly, Cloud Identity-Anthos provides identity services for Anthos environments but does not specifically address the application-level access control like IAP does.