What technique would you use for load balancing traffic for a web application across multiple regions?

Global HTTP Load Balancing is the correct technique to use for distributing traffic for a web application that is deployed across multiple regions. This approach allows you to direct user requests to the closest or most available backend service, ensuring improved latency and optimized performance.

By utilizing Global HTTP Load Balancing, you can take advantage of Google's global network infrastructure, which routes traffic intelligently based on factors such as proximity to the user, backend health, and load distribution. This not only enhances the speed of the application but also provides high availability, as it can automatically redirect traffic away from instances that may be encountering issues or are under heavy load.

In contrast, Regional Load Balancing focuses on distributing traffic within a specific geographical region, which would not be ideal when the web application's architecture spans multiple regions. Traffic distribution via resource cells and HTTP(S) load balancing with health checks also have their uses; however, they do not inherently provide the global reach and efficiency needed to balance traffic effectively across multiple geographic locations.