I am no fan of America's national-security state, which continues to grow steadily larger, more intrusive, and increasingly dismissive of civil liberties. The NSA has removed all expectations of privacy in digital communications, and the TSA is, at best, inept security theater. The Department of Homeland Security's "If you see something, say something" campaign imagines a terrorist around every corner, while the CIA is busy spying on Congress and torturing away the rule of law.

But sometimes, America's intelligence agencies are actually the voice of reason, offering a far less scary view of security threats than public perception or political pontificating provides. But we don't listen.

Perhaps nowhere is this phenomenon more obvious than in an unjustified level of fear of ISIS, says Karen Callaghan, a political scientist at Texas Southern University who researches framing in political discourse about terrorism. If you listen to our hyperventilating national media and bloviating lawmakers, you'd think ISIS presented America with an existential threat. For instance, pointing to media coverage of graphic acts of terror (like beheadings), Callaghan says that this "hyperpublicizing" makes it "difficult for Americans to separate out the truth, difficult to decipher how worried they should be."

Americans are scared of ISIS. More than 70 percent believe that there are ISIS terror cells in the United States, while 90 percent believe ISIS poses a real threat to America, and 45 percent label the threat "very serious."

But that assessment is nowhere close to the reality of the ISIS threat.

Multiple U.S. intelligence agencies have repeatedly announced their consensus that ISIS is not an immediate threat to America. Gen. Martin Dempsey, the chair of the Joint Chiefs of Staff, says there's no evidence that ISIS is occupied with "active plotting against the homeland." DHS reports ISIS is not in Mexico, attempting to infiltrate the southern border. The FBI swatted down any notion that ISIS is planning an attack in the New York City subway system.

This mismatch between public perception and intelligence reports is not unique to ISIS. Indeed, it has been frustratingly consistent in Iran policy for years. No less than 16 American intelligence agencies agreed in 2012 that Iran had no nuclear weapons in development — a conclusion that apparently stands today. But Americans are consistently concerned that the United States is not doing enough to stop the "threat" of Iran getting nukes.

It's understandable, of course, that so many Americans are scared: We are consistently told that we should be, a drumbeat of fear which Callaghan argues "elevates risk perceptions and diminishes the capacity for rational information processing."

Sen. Lindsey Graham (R-S.C.) caught a lot of flak last month for his frantic assertion that failure to adequately fight ISIS means we will "all get killed here at home." Graham completely deserved that flak, but he's hardly unusual in his hysteria. House Speaker John Boehner (R-Ohio) similarly claimed that "we're gonna pay the price" if we don't kill these "barbarians" before they kill us. Across the aisle, Sen. Bill Nelson (D-Fla.) sees a "clear and present danger" in ISIS boasts of flying its flag over the White House, and Sen. Dianne Feinstein (D-Calif.) believes the "threat ISIS poses cannot be overstated."

What gives? "The short explanation... is the incentive structure is such that political figures and public officials can really only be held to account for bad things happening," says Christopher Preble, a foreign-policy scholar at the Cato Institute who studies the causes and effects of excessive fear in politics. Thus politicians tend to exaggerate threats so they can say "I told you so" if the threat comes true — and "Look, I kept us safe" if it doesn't.

Unfortunately, this incentive structure means a great deal of blood and treasure is spent fighting threats that aren't very threatening. Even more fundamentally problematic, Preble argues, "We are terrorized — we are frightened as a society because we are focused on the still unlikely, but understandably frightening, prospect of terrorism." This acceptance of terror plays into terrorists' central goal, which is to force policy change via the demands of a fearful population.

To make matters worse, the policy changes forced by fear often fuel the threat they were intended to combat. For instance, "there's little discussion as to why ISIS even exists, and how American foreign policy has played a part in its development," says Connor Boyack, author of the forthcoming Feardom, which deals with the manipulation of public emotion for political ends. "As a result, Americans end up supporting the very policies that have led to this very problem, and thus are likely to produce similar issues in the short and long term."

Ultimately, what intelligence agencies are saying about ISIS — and the public has so far failed to hear — is that America is really quite safe. As Preble summarizes, "what we're talking about are not existential threats. They're frightening. They're damaging. They're costly. But they're not existential."

So as long as we're stuck with this enormous national-security apparatus, let's at least benefit from its expertise. Let's take their word for it that ISIS is not crouching at the gate. Let's not out-spook the spooks.