As the national narrative shifts from the war on terror to the specter of decline, the uniform performs another psychic function. The military is can-do, the one institution — certainly the one public institution — that still appears to work. The schools, the highways, the post office; Amtrak, FEMA, NASA and the T.S.A. — not to mention the banks, the newspapers, the health care system, and above all, Congress: nothing seems to function anymore, except the armed forces. They’re like our national football team — and undisputed champs, to boot — the one remaining sign of American greatness.

The term most characteristically employed, when the cult of the uniform is celebrated, is “heroes.” Perhaps no word in public life of late has been more thoroughly debased by overuse. Soldiers are “heroes”; firefighters are “heroes”; police officers are “heroes” — all of them, not the special few who undoubtedly deserve the term. So unthinking has the platitude become that someone referred to national park rangers on public radio recently as “heroes” — reflexively, in passing — presumably since they wear uniforms, as well. Stephen Colbert picked up on this phenomenon long ago, which is why he slyly refers to his viewers — and now, to the donors to his Super PAC — by the same term.

“HEROES,” like “support our troops,” was also deployed early, in Iraq. Within a couple of weeks, we were treated to the manufactured heroism of Jessica D. Lynch, the young supply clerk who was rescued from an Iraqi hospital a few days after her capture by enemy forces (both events turning out to be far less cinematic than initially put out) and who finally felt compelled to speak out against her own use as an instrument of propaganda. In the case of Pat Tillman, the former professional football player who died the following year in Afghanistan by friendly fire, not in an ambush as originally claimed, it was left to his family to expose the lies with which the Army surrounded him. The irony is that our soldiers are the last people who are likely to call themselves heroes and are apparently very uncomfortable with this kind of talk. The military understands itself as a group endeavor. As the West Point professor Elizabeth D. Samet recently noted, service members feel uneasy when strangers approach them to — as the well-meaning but oddly impersonal ritual goes — thank them for their service, thereby turning them into paradoxically anonymous celebrities. It was wrong to demonize our service members in Vietnam; to canonize them now is wrong as well. Both distortions make us forget that what they are are human beings.

What is heroism? What kind of psychological purpose does the concept serve? Heroism is bravery and selflessness, but more than that, it is triumphant action, and in particular, morally unambiguous action. In most of life — and certainly in public life — there is scarcely such a thing on either count. Politics is a muddle of moral and practical compromise. Victories are almost always partial, ambiguous and subject to reversal. Heroism belongs to the realm of fantasy — the comic book, the action movie — or to delimited and often artificial spheres of action, like space exploration or sports.

The Marine who saves his buddies in a firefight, the cop who rescues a child from a well — the challenges they face are clear and simple and isolated from the human mess. Capt. Chesley B. Sullenberger III, the pilot who successfully landed an airliner in the Hudson River, was, everyone agreed, a hero. But note how frequently the element of salvation or rescue comes up when we talk about heroism. It was a beautiful coincidence that Captain Sullenberger’s moment came just five days before the last presidential inauguration, for heroism and rescue were the subtext of Barack Obama’s campaign, especially for his legions of young believers. He was the one we’d been waiting for; you could almost imagine the “S” on his chest, underneath the suit. (Once in office, of course, he descended into the muddle, and showed himself a mortal after all.) Heroes are daddies: larger-than-life figures, unimpeachably powerful and good, who save us from evil and hurt.

“America needs heroes,” it is sometimes said, a phrase that’s often uttered in a wistful tone, almost cooingly, as if we were talking about a lonely child. But do we really “need heroes”? We need leaders, who marshal us to the muddle. We need role models, who show us how to deal with it. But what we really need are citizens, who refuse to infantilize themselves with talk of heroes and put their shoulders to the public wheel instead. The political scientist Jonathan Weiler sees the cult of the uniform as a kind of citizenship-by-proxy. Soldiers and cops and firefighters, he argues, embody a notion of public service to which the rest of us are now no more than spectators. What we really need, in other words, is a swift kick in the pants.