Cellphone photos taken by those inside Brussels' main airport and subway early Tuesday rapidly gave the world a horrifying, close-up view of the latest terrorist attack. Survivors of what appears to be at least one suicide bombing staggered with their luggage through the smoking, debris-strewn terminal ruins. Those less fortunate lay crumpled on the floor where only minutes before passengers had queued for check-ins.

A world still grieving for the victims of the Paris attacks is now mourning violence inflicted on another of the world's great cities. Brussels is not only the capital of Belgium but the de facto seat of the European Union. It is also the site of the headquarters for the North Atlantic Treaty Organization, the mutual defense alliance that includes the U.S., Canada, Britain, Germany, France and other European countries.

Responsibility for the attacks has been claimed by the Islamic State in Iraq and the Levant, which is metastasizing across Iraq, Syria and increasingly Libya as it pursues its dangerous goal of building a medieval Islamic caliphate.

Seeing its innocent victims lying in pools of blood provokes undeniable rage. It is a mistake, however, to let anger alone dictate a U.S. response. Bombing the region until the desert sand glows in the dark, as some presidential candidates have called for in response to previous attacks, is a conventional response to an enemy that does not fight conventionally. More force may be necessary, but it must wielded as part of the civilized world's collective strategy.

NATO and the other transnational institutions that call Brussels home are needed more than ever. To their credit, these organizations and their member nations have vigorously responded to terrorism's growing threat. But clearly there's more to be done to eradicate ISIL and aid those fleeing its oppression. A NATO-led effort in particular is essential to roust ISIL from its Mideast strongholds. It shouldn't just be American forces tasked with this formidable assignment.

Closer to home, GOP presidential candidate Donald Trump's wavering commitment to NATO — expressed in a Washington Post editorial board meeting this week — would have been ill-timed regardless but it is really unfortunate in light of the Brussels attacks. Combating ISIL will no doubt be atop the next president's agenda. A strong leader would work to strengthen Western solidarity at this time, not undermine it.