Americans blow hot and cold in their relationship with military. Sometimes the wind changes so abruptly that people the uniformed services don't know what to think. All that warmth feels good when you can get it, but when it disappears as suddenly as it sometimes does, you still have to keep doing your job. The civilian mood-swing is sometimes so abrupt, and so complete, that many people in uniform end up writing off the very civilians they're ostensibly protecting. And the civilians in turn, sensing arrogance on the part of the military, set the thermostat even lower. It's a vicious circle, one that should concern us all.

Love for the military is something Americans are as fickle about as love for this year's "it" movie stars, or the daily stock reports: Military up by three points. Right after 9/11 one of my students, just back from a trip to New York, talked about how nice it was to have people come up to her on the street-she was in uniform- and thank her for defending them. "It's nice to be appreciated," she said, contrasting the way she basked in public approval with the chillier pre-9/11 atmosphere. Back when people still talked about Weapons of Mass Destruction in connection with Iraq-I mean a year or so ago-many service members out and about in uniform felt the warmth of strangers' appreciation: Hey, buddy, thanks.

Now we hear "love the soldier, hate the war," which is a distinction that makes unalloyed feelings difficult. The "support the troops" magnetic "ribbons" only recently all the rage on the back of cars seem to be disappearing the way the football-style American flags on cars did a year or so after 9/11. "Besides," those protesting against the war in Iraq say, "we do support the troops: we want them home alive." That was a position back in the days of anti-Vietnam protests too, but one that took longer to find support among the American people than this one seems to have done.

Now many people in uniform ask, "Where did all that love go?" It's unclear at this writing whether military presence in natural disasters ultimately helps the military's image as humanitarian, or whether it simply dilutes its message. The Pentagon has been involved precisely in this debate outside the U.S.: Should U.S. troops be used as peacekeepers abroad or only as fighters?

These kind of extreme, temporary swings of the love-o-meter are fueled by the larger problem of which this is both an indicator and an example: The military and the civilian worlds don't overlap very much in this country any more. This is the big-ticket worry. The civilian world, at its worst, is opportunistic and selfish with regard to the military-on whose presence they rely in situations of real danger, or when they feel attacked. Send in the Marines! Count to ten and it becomes, "Oh, I don't need you right now; disappear."

Predictably enough, the military responds to such mercurial treatment with a mixture of contempt and wounded pride: Those civilians, they don't understand what we go through, we're morally purer, we're the last best X or Y, it's a decadent society out there, and so on and on and on. I hear all this, and more, from my students, from some career officers in unguarded moments, and from the Marine Corps in its internal U-RAH exhortations to its members. They're in this for the other people who are just as pure/hard/moral as them, not for those soft mall-shopping suburbanites who pay their salaries.

This poses problems. A mutual incomprehension between the military and civilian worlds is a bad thing-indeed, a very bad thing. Andrew Bacevich, USMA graduate and Boston University professor, considers this unsettling phenomenon in The New American Militarism. In a world where almost no members of Congress have been in the military, and where the Pentagon is staffed by career insiders, the military and the civilian politicians who must come to agreement on funding requests speak two different languages.

It's bad for the civilians when they don't understand anything about the military: Te Pentagon can come up with any old thing they absolute need to buy, and the civilians can't distinguish urgent from less urgent. (Remember the famous $1,000 toilet seats of the Reagan years?) It's bad for the military when they are talking to men and women who don't know what it feels like to have been the feet inside the boots on the ground, and who may not even know anybody who has been. Some things that really are necessary don't get funded. (Right now my students are full of stories about troops in Iraq with inadequate supplies. Everybody at USNA, it seems, has a cousin or a brother there.)

Worst of all is the incomprehension, suspicion, and contempt on both sides. There's enough blame for this to go around. However ultimately we have to turn to fixing the problem. The military has to lose the contempt that's all too common for the people they serve; the civilians have to realize that they can't swing wildly between worship and "get lost, I don't want to think about you." The military deserves civilian respect, but in return it has to give respect back.

First step for the military: more openness with the civilian world. Hey. We're on the same side. Tell all you can tell without compromising missions. (And that doesn't mean "embedding" reporters to get artificial "I love these guys" reports.)

First step for civilians: realize that the military is a structural fact, not something you can caress at one point and push away at another. By paying taxes to support them, we say we want them and need them. Act as if that's an ongoing commitment. It is.