One possible cause for the failure of the CloudFormation template to create an EC2 instance in the us-west-2 Region is that the Amazon Machine Image (AMI) ID referenced in the template could not be found in the us-west-2 Region. This could be due to the fact that the AMI is not available in that region, or the credentials used to access the AMI were not configured properly. The other options (resource tags defined in the CloudFormation template are specific to the us-east-I Region, the cfn-init script did not run during resource provisioning in the us-west-2 Region, and the IAM user was not created in the specified Region) are not valid causes for this failure.