Neil Williams wrote:
On 2017-01-22 19:54:36 +0000, Recliner said:

The US ESTA is part of a Visa waiver scheme.

It's a pseudo-visa waiver more like an e-visa system. It's been
proposed that Schengen would introduce something similar. But really
API offers most of the same benefits with less faff.

Yes, I hope API is regarded as adequate for flights within Europe,
post-Brexit.