Brussels was tragically whipsawed last weekend. On Friday, the last at-large attacker from Paris, Salah Abdeslam, was arrested in the city. This well-publicized manhunt provided a sense of closure, and perhaps some relief. So there was particular surprise when twin, coordinated attacks rocked the city only days later.

Monday’s attacks may have been retribution for Friday’s arrest. It is also possible that Monday’s would-be-attackers interpreted Abdeslam’s arrest as a sign that they might be next, so they advanced their planning to strike before they were caught. In any case, the proximate timing may not have been accidental.

And the timing could hardly be worse.

The direct economic effects are likely to be short-lived and generally manageable, as has been the case in London, Madrid and Paris. However, reactionary political effects could become disastrous, particularly if they complicate Europe’s fragile and already-difficult economic recovery. Unfortunately, the pendulum was already swinging in this direction, and it just got a push.

Europe, like America, has experienced a clear swing toward the nationalist and xenophobic right, with calls for greater immigration controls and border security. Brussels is the symbolic center of Europe, but a truer center is Germany. And German Chancellor Angela Merkel’s centrist party, the Christian Democratic Union, was recently upset in a regional election from an up-and-coming right-wing nationalist party.

The likely upshot of Monday’s attacks in Brussels is an exacerbation of this trend, with the attendant risk of converting a tactical tragedy into a strategic threat. Moreover, this is precisely what the terrorists hope to achieve.

Terrorism is profoundly inexpensive and asymmetric. Moreover, it is effective because its victims often react in predictable ways that enable the terrorists' goals. For example, a natural response is to demand more security, which often has the ironic effect of making the victims even less secure.

The fear of terrorism taps into a primal part of our evolutionary brains and hijacks rationality. This counterproductive tendency can spiral, as Americans have seen, to the point that torture becomes not only prescribed but widely tolerated. And this phenomenon is only becoming more potent with the digital echo chamber of social media and its tendency to polarize and misinform.

While instinctive, such a counterproductive response would exacerbate the problem of European Muslim assimilation and the compounding challenge of millions of refugees displaced into this witch’s brew. It is difficult to overstate the magnitude of this problem in Europe. In Germany, Muslims are approximately 6 percent of the population and growing. And Germany’s economic strength and their generally favorable views of Muslims have created incredible immigration pressures, fueling the nationalist fervor.

Even in the United States, with less vexing demographics, the challenge is formidable. President Barack Obama was pilloried in the wake of the San Bernardino attacks for his “stoic” approach by fearful Americans who looked past the fact that he was making a deliberate show of resilience. However unpopular, this is the best defense in the face of terrorism, because it denies the terrorists the fear they seek to create. A true show of strength is in the power of resilience, not in the emotion of lashing out.

Recurring victims of terrorism become familiar with the effectiveness of resilience, not so much as a feigned posture, but as a conditioned necessity. Take Afghans, for example. When the Taliban detonates a bomb on the streets of Kabul, the mess is cleaned up, windows are repaired that same day, and business resumes with a stunning reset to normalcy. Europe can’t afford the decades of conflict that left the Afghans so hardened. In the wake of these episodic attacks, the emotion and grief needs to find its way toward a deliberate and deterrent strategy of resilience.

Paul Slovic, a professor of psychology at the University of Oregon and an expert in risk perception, advocates countering terrorism with “pseudoinefficacy,” a simple concept that tries to affect the psychological calculus of any would-be attacker, de-motivating them by denying them the effect they seek. The idea is to make their act seem futile or, as Slovic says, a mere “drop in the bucket.”