Any 'gcloud compute ...' command results in Error: "Request had insufficient authentication scopes"

[gbergeraph]

Have had a GCE instance for a long time.  Created another and am trying to ssh into either from the other.  Both instances belong to the same project, one is on us-central1-c, the other is on us-central1-a.

From either instance:

• The 'gcloud compute ssh ...' command fails with "Request had insufficient authentication scopes" in either direction.
• 'gcloud compute images list' also fails with the error.
• gcloud compute project-info describe --project (project name) fails with the same error.

Any ideas what's happening?  Where would I find/set authentication scopes to allow ssh from one instance to the other?  Or even list information?

Any thoughts appreciated.