Drivers in Atlanta burn their headlights in rush-hour traffic to symbolic support for the American hostages n Beirut. Radio deejays cue up a country-western tune that calls the terrorists ''chicken Shiites.'' A frustrated computer technician camps out on the steps of the U.S. Capitol to talk antiterrorism to tourists. And telephone calls of outrage and support light up the White House switchboard.

The remaining hostages in Beirut aren't the only Americans under the gun of international terrorists. They're not alone in their confusion, frustration, anger and fear. Psychologically, experts say, every machine gun-waving hijacker holds at bay a nation of ''indirect hostages.'' Every exploding bomb claims a nation of ''indirect injured.'' Many of the same elements of mental and emotional duress that line the televised brows of actual hostages attack vicarious victims thousands of miles away.

What is a healthy and constructive response to terrorists' atrocities for those of us who confront them at ocean's length -- on the screens of our televisions and in the headlines of our newspapers?

Some terrorism experts insist the answer to that question is, in the long run, more important than the political or military answers we impatiently search for to resolve the current crisis. How the actual captives of terrorists hold up throughout their trauma may determine the victor of a single battle -- but how a nation of ''hostages'' responds determines who wins the war.

''If they're gonna use U.S. citizens as pawns, then we're gonna talk back,'' Chris O'Donnell says from his Gaithersburg home. Last week's hijack of TWA Flight 847 and the murder of hostage Robert Stethem enraged O'Donnell, 21, and his housemate Jerry Frishman, 25. They had to do something. Their response: Manufacture T-shirts bearing a terrorist-busters emblem -- ''USA For Freedom'' T-shirts. Their plan is to donate a dollar from the sale of each T-shirt to a hostage-relief fund for Stethem's family. ''If 100 shirts sell, that's 100 people who've stood up and done something,'' says O'Donnell, his voice quivering with anger. ''If 10,000 sell, well, that's 10,000 who are telling that family their son mattered. I want it stopped. I want to do something about terrorism. I'm trying to do something good for the country.''

Jim Mullin of San Diego is less certain than O'Donnell about his reaction to the latest terrorist strike. The editor of the San Diego Reader admits his thoughts seem frighteningly surreal to him, out of sync with his most guarded values. ''I just want to punch the walls,'' says Mullin, 35. ''But it does scare me when I think how quickly I can rise to contemplative violence that I would normally never endorse -- or consider.''

A terrifying aspect of terrorism is its intent to infiltrate the minds of the citizens of its target society, creating confusion, chaos and alienation that chips away at public and personal confidence. Former U.S. ambassador to the United Nations Jeane J. Kirkpatrick described terrorists as ''the shock troops in a war to the death against the values and institutions of a society and of the people who embody it.''

The current crisis, say experts, may be ''watershed'' for the United States. Americans, for the first time, are now grasping that ''we are the target'' -- directly or indirectly.

''This is a kind of psychological Pearl Harbor -- we are under attack,'' says Stefan Pasternack, associate clinical professor of psychiatry at Georgetown University. ''The terrorists are attempting to manipulate our emotional reactions.''

How we, a nation under psychological siege, will react to a coming world in which terrorists are regular tenants is unclear, says Robert Phillips, associate professor of philosophy at the University of Connecticut, Storrs. Phillips directs the university's Program for the Study of War and Ethics that provides curricula on terrorism to West Point.

''What we have to understand is that the purpose of the terrorist is to directly attack innocent people . . . in the hopes of convincing the rest of the populationthat their government cannot protect them,'' says Phillips, who foresees an increase of terrorist activity on U.S. soil. ''They want to detach the sense of obligation and loyalty to government.''

Psychologists say a pattern ofreaction to the overpowering attack of terrorism exists and can be predicted -- to a point.

''People initially respond by re-defining the situation,'' says Irene H. Frieze, professor of social psychology at the University of Pittsburgh and a member of the American Psychological Association's task force on victims of crime. ''They say, 'I'm not really like them. I don't travel around the world. I don't care about the Middle East.' So that it isn't really as threatening as it seems to be at first glance. It's restoring a perception of invulnerability that whatever happens to other people won't happen to me.''

Failure to defuse the threat through redefinition leads to the second typical response: anger or frustration. ''Technically, we call that a 'reactance,' '' says Frieze, characterizing it as an emotional flailing about in search for a way to change the situation.. Reactance, she says, is the point most Americans have reached in their response to the current crisis.

''A crime victim will sometimes express this reactance by lashing out at his own family -- that's negative,'' says Frieze. ''It can be channeled in a positive way by doing something concrete, no matter how small. Wearing the ribbons during the Tehran crisis was a response that said, 'We stand together.' What you need to do psychologically is make the problem into something manageable.''

The third reaction -- an overwhelming feeling of helplessness -- affects those who fail to make the situation personally manageable. Rona M. Fields, an Alexandria clinical psychologist and sociologist who consults for businesses and federal agencies on terrorism, has seen the ''powerlessness that paralyzes any potential for action'' during frequent visits to terrorized Northern Ireland and shell-shocked Lebanon.

''Once a person begins thinking of himself or herself as an object, [he] becomes more vulnerable. That vulnerability feeds on itself,'' says Fields. ''The psychology of the terrorized is the identification with the victims through which one vicariously experiences this helplessness and becomes really unable to do anything that's effective in real life.''

How can the individual indirectly confronted by the horrors of terrorism act effectively? Experts on terrorism have identified these 12 healthy and constructive personal responses:

*Restore your sense of invulnerability. Simple actions that require little agonizing can accomplish this. ''It may be healthy to decide not to travel to those areas under attack,'' says Frieze, citing President Reagan's warning about the Athens airport as a positive measure. ''You've got to think about action you can take -- within the law -- so that it's unlikely to happen to you.''

Paul Goodwin, professor of history at the University of Connecticut who specializes in the roots terrorism, says a sense of invulnerability can return with some basic facts: ''If you consider the number of planes flying each day and weigh that against the number of incidents, you really have to conclude that it's pretty safe.''

*Don't overreact. While experts agree that some fantasizing of vengeance and retaliation can be a harmless vent for built-up anger, it has its limits.

''It's very easy to want to lash out, bomb somebody,'' says Goodwin. ''But if they can provoke that response, especially an extra-legal response, then you're dancing to their tune. Once you start playing the terrorist game, you've lost.''

Adds Thomas Courtless, professor of law and sociology at George Washington University: ''Here I am, a professor. I'm supposed to be educated and rational. I really get steamed up . . . They get a foothold when they get us to think that way.''

*Find a way to help. ''A helping response is a way of reassuring your sense of confidence and your sense of control,'' says Frieze, ''and it makes you feel good about yourself. Send a note of support to the hostages' families. Offer your assistance with relief efforts.''

*Rsist resignation. ''Resignation is the first attitude one finds in Ireland,'' says Phillips, adding that while accepting the presence of terrorism as a fact of life is positive, accepting it as a norm isn't. ''The British are probably second only to the Israelis in handling terrorism,'' explains Phillips, ''and they have been ineffective in eliminating it from British territory. We won't be able to either, but we have to keep trying.''

*Avoid bunker mentality. ''A group that finds itself singled out and threatened because of its identity sometimes takes on a siege mentality,'' says Fields. ''First you think that everybody out there is the enemy. You become afraid to talk to someone very different from you. They you stop seeing yourself as a reasonable human being and you hunker down, keep a low profile and hide behind barbed wire. Absolutely nothing is accomplished if that mentality prevails, because you're too tied up in neurotic little knots to go out and do anything.''

*Emphasize a sense of continuity. ''In North America, it seems like there's no past or future,'' says Gerald Sarwer-Foner, chairman of the psychiatry department at the University of Ottawa School of Medicine. ''There's just now. One of the ways ordinary people can be helped to react to terrorism is if they understand they are part of a continuity themselves. These United States will continue and Canada will continue. Continuity offers hope. The stiff upper lip.''

*Maintain a sense of community. A terrorist's goal is to fragment society, says Sarwer-Foner. ''Frightened, isolated and alienated people with no sense of community are particularly vulnerable to terror. People today don't have the sense of community and belonging that they've had in the past. Community means we are in this together. There has never been a case in recent history where terrorism has worked where a whole society holds together.''

*Cooperate with government security. Increased precautions, such as longer waits at airports for baggage inspection and tighter security in public buildings, will require patience and understanding, says Phillips. ''If you go through Northern Ireland, you see large billboards that encourage citizens to call anonymously about suspicious activities. There has been an extensive public relations campaign to inform people about the dangers of terrorism. The Israelis have a similar program that has been even more effective. They've got 'block watchers' -- individuals who are responsible for watching out to see if any suspicious characters are around. They've asked citizens to put up with searches and metal detectors at places like large shopping centers.''

*Guard constitutional freedoms. An easy answer to combatting terrorism is placing restrictions on freedoms guaranteed by the Constitution, says Bernard Reich, professor of political science and international affairs at George Washington University. ''If you give in by restricting your freedom, then the terrorists have won,'' he says. ''You've become a different kind of society. It's a lot easier to give security in the Soviet Union, but I don't want to pay that price. I'm already depressed when I drive by the White House and see those concrete barricades.''

*Reach a national consensus. ''A healthy thing for the American public to do is call for a national consensus to decide how to deal with terrorism,'' says Pasternack. ''it's time to galvanize our will, formulate a plan of action -- not take it passively. When you pick up the challenge and organize your forces, you are no longer the helpless victim, no longer a captive.''

Pasternack compares the action to achieve a consensus to the public push to form civil defense leagues when faced by the prospect of the atomic bomb. ''The longer we do nothing, the more we are subject to a national despair. What's our mental bomb shelter going to be for terrorism? We have to get to work.''

*Educate ouselves about terrorists and their issues. ''Be better informed about terrorism -- why it's happening, its history, its purpose,'' says Courtless. ''As much as none of us want to admit it, often terrorism has its roots in some real issues -- significant ones that we're going to have to address.

''But it's a vicious circle. I overheard a guy on the subway talk about the Shiite leader Nabih Berri claiming that Americans refuse to listen to their side of the problems, and the guy snaps, 'Who the hell does he think he is?' I'd say the odds aren't good for public receptiveness to all the issues -- but that's exactly what we need to deal effectively with terrorism.''

Goodwin says our national inclination to see issues as black and white blocks ou progress toward resolving terrorism in general. ''Give us good guys and give us bad guys,'' he says. ''The majority of Americans consider terrorists to be crazy or psychotic. The majority of them are neither. Most are perfectly rational -- but desperate. We need to understand the desperation.''

*Uphold American character. ''We need to remind ourselves and each other who we really are,'' says Fields. ''We are not helpless, poverty-ridden victims of despotism who have no way of expressing ourselves but to bow and scrape. We are free people who have an advanced level of civilization. And we need to muster that civilization. We are not relegated to bouncing grenades off each other like they are. We are able to cope.''

Adds Pasternack: ''We need to make a healthy reaction come out of this -- one that conforms to our national ideals and character, one that conforms to our national ideals and character, one that conforms with how we psychologically identify ourselves.

''That's the challenge of terrorism. If we change too much, then they have a victory and they've made us into monsters.''