If the entire source Region fails, can we launch an EC2 instance using the copied AMI?
Yes, absolutely. If your entire source Region suffers a catastrophic failure, you can use the copied Amazon Machine Image (AMI) to launch a fully operational EC2 instance in your destination Region.
This capability forms the foundation of robust Cross-Region Disaster Recovery (DR) strategies on AWS. Because the copied AMI is structurally and operationally isolated from the source region, it remains fully accessible even if the source region goes completely offline.