People on twitter seems to think this is the -end- of American tourism for Europe, funny how just bringing the same standards suddenly makes us a no-visiting place.

FFS

It's a power game. Presumably less Americans visit places that require visas since there are enough places that don't. So Americans may not want to go to Europe as much. Currently plenty of European tourists go to America, so maybe that doesn't bother them as much. Pick a third world country like Jamaica. Americans can go there visa free, and Jamaica wants Americans to continue to come, so it stays visa free. However Jamaicans require Visas to go to the US, because the US had decided that it doesn't need to encourage Jamaicans to come to the US, enough already do.

Maybe someone could analyze from 2009-2010 data, did the introduction of ESTA have any effect on how much Europeans traveled to the US.

Americans have many destination options, including America. Any barrier is going to reduce the number somewhat

Presumably it also means some number of Americans are going to be legally prevented from entering Europe when they wouldn't have had any trouble under the old system.

Yeah, it's just hyperventilating. If I'm spending five-digit sums of money on a trip to Europe, an extra $10-20 per person for some electronic nonsense is not going to stop the trip. It's a hassle, sure, but a pretty small one.

Should it be seen as retaliation, or just rational decision to prevent illegal or unwanted migration?

I think you will struggle to find numbers that support a high degree of illegal immigration from the US to the EU, and retaliation, justified or not, is the much simpler explanation. For unwanted but legal immigration, this has no impact.

According to that Wikipedia page, this looks very similar to the ESTA.

Having had to apply for that last year, it's not at all clear to me how that could help prevent any kind of illegal or unwanted migration. It's not rocket science to say that "yeah, you're only visiting for a few days and that yes, you intend to go back".

So I think it absolutely is a political circus, aka retaliation.

Just like during COVID, when at one point cases started taking off in France again, some country (can't remember which, might have been the UK) started asking for a negative test before entering. Wouldn't you know it, the next day it became mandatory for people coming in the other way. Cases hadn't moved in that other country.

Retaliation is basically the default for visas. The data obtained from the ETIAS is no better than what they get from the airlines (APN) or scanning passports at the border.

Not just the US - Brits will have to do it too. Thanks, Nigel!

Not only has the US unilaterally introduced these requirements already 15 years ago, but there are still 3 EU countries (Bulgaria, Cyprus, and Romania) that are not even in the Visa Waiver Program - so I think some "retaliation" is in order...