Despite these dangers, there is a case for attacking ISIS. Part of it is humanitarian: Millions of people now live in a caliphate in which many women cannot leave their homes unless accompanied by a man, and religious minorities can be sold as slaves. Allowing ISIS to expand, and potentially threaten Jordan or Saudi Arabia, would produce misery on an epic scale, intensify the refugee crisis already roiling Europe, and destroy America’s reputation as the underwriter of Middle Eastern order.

But the war isn’t being sold on these grounds. The presidential candidates are not telling Americans that a greater short-term terrorist threat is the price they must pay to liberate oppressed Arabs, protect friendly regimes, and prevent a greater danger down the road. Instead, candidates are promising, at least implicitly, that if America intensifies its war, the terrorist threat will decrease.

What happens when they’re proved wrong? In a political environment where candidates won’t admit that ISIS attacks are partly a response, albeit a monstrous one, to the United States’ own use of force, further attacks will leave Americans even more bewildered and terrified than they are now. Some will gravitate to politicians who promise that with greater force, including ground troops, they can deliver a decisive military victory. Other Americans, desperate for a quick fix, will support further assaults on the rights of Muslims in the United States. Both impulses will help the Islamic State. And America will slide deeper into the terror trap.