WASHINGTON: Will it be like a hunt for a “loose nuke,” as in the movie “The Sum of All Fears”? Or will it be an atomic barrage, between, say, India and Pakistan — an exchange that analysts say could kill 12 million people?

Throughout history, works of imagination, written and filmed, have helped ordinary people anticipate future events, including future conflicts. During the Cold War, when new technology offered a not-so-distant early warning that human action could bring the world to a end, millions of people became involved in test-ban and arms-control causes.

They were inspired in part by novels such as Nevil Shute’s “On the Beach” (1957), Peter George’s “Red Alert” (1958), and Eugene Burdick and Harvey Wheeler’s “Fail Safe” (1962). These books were turned into apocalypse-portending movies as well. “Red Alert” became the lethally funny “Dr. Strangelove.”

But did all this popular reading and movie-watching help? It’s impossible to unbraid the tapestry of the past, but since we got through the Cold War, from the ‘40s to the ‘80s, without firing a nuclear shot in anger, it’s hard to deny that, whatever we did, we worked it out well enough.

Indeed, continued pressure from national and international public opinion helped spur the United States and Russia to sign, last month, a two-thirds reduction in their nuclear arsenals over the coming decade, further lightening the atomic shadow of the last half-century.

But, of course, other kinds of threats, not all of them nuclear, continue to lurk. The question before humanity is whether the doomy speculations of fantasists will become the gory death plans of madmen — and then, whether society can look ahead and forestall such horror shows.

Alas, the past record of looking ahead is not encouraging. French author Jules Verne imagined chemical warfare — with what he called “asphyxiation bombs” — in his 1889 short story, “In the Twenty-Ninth Century.” Yet disastrously, his own countrymen didn’t think to factor this suggestion-warning into their own war planning.

They were clueless when the Germans used gas clouds on World War I’s Western Front 26 years later.

But it might have been some consolation to those gassed soldiers that, after the fact, chemical warfare was banned and has mostly stayed banned ever since.

But, of course, bans can be broken as new situations arise. The Los Angeles-based Simon Wiesenthal Center recently reported that a West Bank Palestinian, arrested May 9 by the Israelis, confessed to plans to add cyanide, made in clandestine local labs, to suicide belt-bombs. And near Mexico City in May, truck- jackers made off with 7.6 tons of sodium cyanide. Most, but not all, of this toxic cargo was apparently recovered this week.

In addition to chemical weapons, biological killers have long been a fictional preoccupation, as seen in stories such as H.G. Wells’ “The Stolen Bacillus” (1895) and in movies such as Terry Gilliam’s “12 Monkeys” (1995). And yet with a century’s worth of advance warning, how good a job have the nations of the world done in preparing for a future bio-strike?

If last fall’s mail-borne anthrax attacks are any indicator, even small assaults can wreak huge amounts of economic, psychic and physical damage. Congress just passed a $4.6 billion anti- bioterrorism bill, including $640 million to produce and stockpile smallpox vaccines.

But maybe the emerging science of the human genome is about to leapfrog the old mechanisms of biodefense. Who says so? One possible prophet is Walter Mosley, best known for his “Easy Rawlins” crime novels. Last year, Mosley published “Futureland: Nine Stories of an Imminent World.” In one tale, “The Nig in Me,” set in the middle of this century, war escalates from nukes to race-based viruses.

One bug, Mosley writes, “was 100 percent fatal and everybody got it; everybody but those with at least 12.5 percent African Negro DNA.”

The notion of a disease targeted to a specific ethnic group is so abhorrent on so many levels that it would be hard for Americans even to begin a discussion about dealing with that threat.

But as history proves, if somebody can think up a weapon, somebody else will think up a way to use it. And it’s everybody’s responsibility to help fend it off. —Dawn/LAT-WP News Service (c) Newsday