Ariana Grande, Counterterrorist

A week after the terrorist attack at her concert in Manchester, Ariana Grande and a slew of other megastars returned to the city for a concert raising money for victims of the attack. What stood out about the performance was not so much the performers, but the crowd. The catharsis was palpable, as was their celebration of solidarity. Whether she realizes it or not, Ms. Grande organized a powerful act of counterterrorism.

Counterterrorism is more than policing at home and warfighting in distant countries. Effective counterterrorism requires resilience. The concept is straightforward. Society is stronger when it can bounce back from a terrorist attack. Often the focus is on hardened infrastructure and a capacity to get businesses up and running again. When done right the hope is to dissuade terrorism. If the target can easily slough off an attack, why bother?

The concert by Ms. Grande and others illustrated a different kind of resilience. It was a declaration of prosocial and cosmopolitan values — the very things under assault in recent attacks in Manchester, Baghdad, London, Kabul and Portland. The theme throughout Monday’s concert was to move forward in solidarity and love.

Solidarity is an important counterterrorism tool. It is produced through common experiences and reflects a dedication to building social capital that promotes an expansive and inclusive political community. The concert goers in Manchester reveled in precisely this. Halfway through the show, Ms. Grande told the crowd, “The kind of love and unity that you’re displaying is the kind of medicine that world really needs right now.”

The medicine of solidarity is more than a salve to make us feel better. It is a prophylaxis that makes us safer. The opposites of solidarity — fragmentation and alienation — foster violence. Society is weakened when we look at one another with suspicion or with the simplicity of stereotypes.

Solidarity is especially fragile at a time when violence comes so easily. All it takes is a knife or a car to upend a community. There is no need for a sophisticated terrorist organization to perpetrate such attacks. The bar is low for any individual craven enough.

Just as violence comes easily, so too do ineffective kneejerk counterterrorism policies. In the aftermath of terrorism government officials often clamor for more surveillance at home and more bombs abroad. It is true that these policies sometimes deserve consideration, but they require a delicate touch and a long-term perspective that is rarely found in politicians. When heavy handed counterterrorism policies go wrong, the damage can be significant. Cherished freedoms are eroded at home. Unnecessary devastation and war is unleashed abroad.

Solidarity, on the other hand, is a risk-free counterterrorism force. It is a power that is fundamentally productive and lacks the coercive edge that often feeds cycles of violence.

Governments cannot legislate solidarity. This is why Ms. Grande’s concert was so important. It didn’t just call for solidarity, it performed it. But the performance that mattered most was the crowd’s as it sang in fellowship and dedication to virtues that create, rather than weaken social bonds. The evening’s closing cover of “Over the Rainbow” was particularly fitting. The song reflects a dream of a better world. In that spirit Ms. Grande’s concert provided a space for Manchester to dream together in solidarity, a valuable response to those who are bent on producing the opposite.