Using fear to get ahead in American politics might not be a new phenomenon, but it is more dangerous than ever. Consider the difference between the discussion of terrorism today and, say, the missile gap debate in the 1960 election—an issue of truly existential dimensions. The Politburo was not going to launch a nuclear strike against the United States because of our presidential campaign or our national mood. But ISIL and Al Qaeda in the Arabian Peninsula—which is still the jihadist group most likely to carry out a major strike against U.S. interests—will undoubtedly be more motivated to attack us because we, as a nation, are afraid. Homegrown terrorists—as Farook and Malik appear to have been—will also see a greater reason to act now given the potential for overreaction and political crisis.

Closely linked to the issue of fear-mongering is the Islamophobia now surging through the body politic. Republicans may be congratulating themselves for denouncing Trump’s latest vicious buffoonery—his proposal to bar Muslims, including American citizens, from entering the country. But many of them are enjoying cruising in his slipstream. Where were they when Trump declared that the way to defeat terrorists was “to take out their families” in contravention of the laws of war and more than 200 years of United States military practice?

Comments such as these perfectly validate the part of ISIL’s narrative—which it appropriated from Al Qaeda—that says the West seeks to destroy Islam and its believers. The same is true for all the menacing rhetoric about creating national registries for Muslims in the United States and for cutting off Muslims from their families abroad. Proposals like these further undermine one of the most powerful claims America makes to Muslims abroad in its public diplomacy—namely, that the United States is a safe haven from the violent hatreds now roiling the world.