I am arriving in Brussels. The train from London is full of the usual Chinese tourists and bored businesspeople. The city doesn’t, contrary to the impression given by CNN, resemble Kabul. Rows and rows of untouched houses scream bourgeois calm (actually, they gently whisper bourgeois calm).

As I wander out of the train station, grim-faced soldiers with impressively large automatic weapons are rousting a homeless man. He doesn’t look dangerous. There is no gunfire or explosion going off in the background. Daily life in Brussels continues in its usual sunless stupor.

Outside the train station, I think of the 31 people who were so tragically killed in the metro and at the airport while innocently going about their daily lives. I am helpless to resist imagining myself or my loved ones in their place.

But as I watch the Brussels traffic, I’m also thinking about the two or three people who, statistically speaking, died in road accidents that same day in Belgium. They were also going about their daily lives and probably also died tragically.

But we will not have protest marches for them or newspaper profiles lamenting their loss. In fact, we will never know, or apparently care, who they were. Still, there are two or three more of them every day.

Similarly, there were 372 mass shootings in the United States in 2015, killing 475 people and wounding 1,870, yet ending this killing spree is a minor issue in the presidential campaign. But a terrorist attack in a city an ocean away that killed far fewer people has already roiled the campaign.

Along with many, many others, I’ve been researching and writing about this disproportionate reaction to terrorism for more than a decade — about the dangers it poses to freedom and democracy, and even the ways it can encourage more terrorism. President Barack Obama seems to agree.

Yet it is abundantly clear by now that these arguments, as strong as they seem to me, will never have an impact.

Indeed, a phone call from the US reminded me that I haven’t even convinced my own mother. She was not happy that I had dared to visit Brussels. She advised me to stay away from crowds. She loves me, but her fear is stronger than her faith in my analysis (which, she assures me, she does read).

The difference between her image of Brussels and its reality is hardly surprising. Back in the US, the media hype surrounding terrorist attacks, the fear it generates among the public, and the exaggerated policy responses that public reaction inspires in politicians are all now part of the routine.

Why? Why do we continue to choose fear? Why do we care so much more if you are killed by a terrorist than by a drunken driver or an apolitically deranged individual with a gun?

Over the years, I’ve observed three main reasons:

1) Human inability to differentiate anecdotes from probabilities

Humans evolved in small communities of a hundred or so individuals. If you live in a community that size and a bear eats someone, it makes sense to take measures to avoid bears.

But if you live in a community of 300 million people (the United States) or 7 billion people (the world) and a bear eats someone (even if it is on live television), it makes little sense to change your life at all.

People simply cannot understand this at a gut level. Numbers like 300 million or 7 billion are just too large for human beings to really understand. Faced with such numbers, human probabilistic reasoning derives more from anecdotes than statistics.

Statistically speaking, because I am at greater risk from traffic accidents than from terrorism, my mother should have advised me to stay off the roads, not avoid Brussels. But she is not alone in her reliance on anecdotes. Indeed, without this genetic flaw, terrorism would not exist to exploit it. (Nor would the lottery, but that is another story.)

2) Media saturation

Constant, global media coverage means that we now apply our faulty probabilistic reasoning to a global supply of anecdotes. The intense media coverage today has made terrorism a much more effective tactic than it was once was.

As a popular chart that made the rounds on Twitter this week reminds us, the terrorism problem in Europe was much worse in the 1970s and '80s than it is today.

Terrorism in Europe. The horrors of the 1970s and 1980s put today's problems into perspective. pic.twitter.com/jN7pDwfBn4 — Paul Kirby (@paul1kirby) January 15, 2016

The 85 people killed in the 1980 train station bombing in Bologna, Italy, died just as CNN was launching and thus did not enter American consciousness.

Today, a bombing in a Brussels metro station is drummed into our heads in real time through constant stories and vivid pictures. It feels like an attack on our own community.

3) The tendency to overestimate foreign enemies

Deaths from foreign enemies inspire a special kind of fear. We tend to assume that foreign threats, particularly those we only dimly understand, are beyond the control of normal law enforcement, are powerful and strategic in their thinking, and have the capacity to grow and ultimately destroy our societies.

There is a logic to this idea. Deranged loners may be more likely to kill people than terrorists. But after a deranged loner shoots up a mall, he doesn’t get together with his deranged loner friends in a safe house in Syria to celebrate the success, learn from the experience, and plot further attacks. Terrorists do.

It is easy to believe that the deranged loner threat will always remain roughly what it is, whereas the terrorist threat might grow without bound. The popular, albeit exceedingly improbable, idea that terrorists might acquire nuclear weapons extends this fear to its logical conclusion.

But in fact, terrorism is the weapon of the weak, and its very use demonstrates a certain level of desperation. Research shows that groups using terrorism seldom win or even gain concessions. It is therefore no surprise that ISIS is resorting to terrorism in Europe now that it has started losing the war on the ground in the Middle East.

We have met the enemy, and he is us

As President Obama has found, there is little that policymakers can realistically do about society’s irrational fear of terrorism.

Forcing people to go to class to learn statistics, probably the most effective thing we could to do to make society more resilient to terrorist attacks, would be even less popular then drafting them into the army to go abroad and kill terrorists. Attempts to limit or control media coverage would be ineffective and unconstitutional. Efforts to wipe out foreign enemies, even when they work, simply generate new and angrier foreign terrorists.

Policymakers and politicians know that if they fail to acknowledge people’s fears, however irrational, they will soon cease to have jobs. So they rightly ignore people like me telling them that terrorism is not such a big problem.

The conscientious ones look for ways to channel those fears into more productive activities, such as increasing societal resilience to terrorist attacks. They seek to play down the threat of terrorism to the extent possible and enlist communities in the effort to prevent young men (and women) from turning to the dark side.

The more cunning ones look for ways to play on the fear. They often recommend policies, such as Republican presidential candidate Ted Cruz's proposal to patrol and secure Muslim neighborhoods, that nearly all experts say would only make the terrorism problem worse.

It is this terrifying symbiosis between the terrorists in the Middle East and the populist politicians in the West that is the real threat.

But don’t worry, Mom, I’m leaving Brussels tomorrow.