“I wouldn’t take that trip to Brazil, if I were you.”

Why?

“What if you can’t back in the country?”

This exchange with a friend took place when I said that I have several international trips coming up on my schedule. In response to his paranoia, I pointed out that this is an absurd fear. Mexico, Brazil, and the Czech Republic are not on Trump’s list. Plus, I’m an American citizen. There’s absolutely no question that I can leave the country and come back.

And yet, I was slightly lying about my confidence here. The truth is that this fear had already occurred to me. With the stroke of a pen, Donald Trump invalidated as many as 60,000 green cards and visas that had already been issued to citizens from eight different countries. One moment, they were research scientists, programmers, and students living in the US. The next moment, they were stranded outside the borders, patrolled by tough border agents with power.

You could say it is an irrational fear. Maybe it is not. Could that happen to me? Probably not. Oh, surely not. That’s absurd. And yet we know the power is there. We think about it every time we come into the country. We stand there faced with some badged dude we don’t know. He examines our papers, affecting an air of suspicion. He slowly picks up some stamp thing. He pushes it down, and says something or nothing and hands us back our passports.

There is not one person who has gone through this process who, at that moment, doesn’t breathe a sigh of relief.

So when the President suddenly slams the door shut, in a way over which we have zero control, sure, the sense of anxiety increases. You can say it is irrational. But actually, maybe it is not.

After all, I’ve been variously detained at borders for no reason. I was held for 30 minutes once when trying to get out of Brazil to return home. I never found out why. Entering Canada, I had my cell phone confiscated and was held for interrogation for two hours, solely because some agent found my bow ties suspicious. Because why? Canadians don’t like bow ties? I never found out.

I’ve never had trouble getting back across the US border, but there’s always a first. Plus, the chances will grow after this article because, as it turns out, agents are now checking Facebook profiles for anti-government postings. All these revelations intensify public anxiety.

The Fear Is Widespread

It turns out I’m not alone in my fear here:

US airline and online booking agency shares slumped for the second consecutive day on Tuesday, and some industry executives have begun speaking out against the Trump administration’s ban on travel from seven majority Muslim nations.

Share prices of major US airlines and third-party travel booking sites have plunged since Friday when President Donald Trump issued an order temporarily barring entry to the United States from nationals of seven Muslim-majority countries. Confusion over who was affected, and protests at some major airports, disrupted travel throughout the weekend.

Some travel agencies report that their business is down between 20% and 50%. This is obviously very bad for business. Presumably this was not the purpose of Trump’s executive order (I say presumably because government always benefits from a panicked public.) But it does illustrate the general point: attacks on anyone’s liberties end up as an attack on everyone’s liberties.

You could respond that the travel-ban list is restricted, and the conditions well-defined. But what matters in fact is that which countries were and were not on the list was ultimately the decision of one man, and there is nothing but perhaps some interventions by a few judges that stands in the way of Trump’s decision to bar border-crossing from other countries.

For example, I’m headed to Mexico soon. Since Trump’s inauguration, the relationship between Mexico and the United States has become tense. What if some incident happens in the US or Mexico while I’m out of the country? What if Mexico is added to the list? What if the conditions are expanded to the point that even American citizens are affected (because, let’s say, there are reports of fraudulent passports)?

Let’s add this immigration ban to the incredibly long list of policies designed to achieve one thing that ends up doing something else.Yes, the possibility is remote. Extremely remote. But even the slight chance of the worst possible thing happening is too much when the trip is entirely optional, and especially given that most people feel a sense of vulnerability when out of the country.

Then you add the new rule that the IRS itself can revoke your passport if you have tax troubles – news which adds more anxiety given the tendency of this agency to overreach and be downright wrong.

Being trapped so that you can’t get into the place you call home is a truly terrifying prospect. Being locked up abroad is a culture-wide fear.

It is for this and other reasons that technology companies – which operate in a borderless world – have shifted from grumbling about the actions of this administration to full-scale and very vocal opposition. Companies are rethinking plans even to open shop in the United States. Moving abroad – ultimate irony – is looking ever more attractive. 

Let’s add this immigration ban to the incredibly long list of policies designed to achieve one thing that ends up doing something else. As Trump’s own Alma Mater editorialized, “the travel ban could end up making U.S. citizens feel more insecure, rather than achieve its stated objective of enhancing safety.”

Speaking for myself, I’m feeling it.

The big question for the courts right now is whether this ban was legal. I don’t know the answer to that. But this much I do know: it has made the world a less stable and more scary place, and that’s never a good plan for restoring greatness.

There’s never been a better time to rally around some old ideals such as the rule of law, peace, human rights, liberties, and so on. They really do matter. The quality of our lives depends on them.

This article originally appeared on FEE.org.