The Vietnam War was the ultimate quagmire; it perplexes still today. It remains the longest war in American history, yet no formal declaration of war was ever made. In 16 years of carnage and terror in Southeast Asia, the United States never once engaged its actual adversary, the distant Soviet Union. A thing of illogic, the Vietnam War was impervious to reason. War protesters eventually realized that they needed a tool more potent, yet more vague, than logic, so in 1969 they organized a worldwide protest, which they called the Moratorium, for which Jasper Johns created a flag. It is one of the most powerful pieces of anti-war art ever produced, and a peculiarity in Johns’ body of work. At the Albuquerque ROADSHOW in July 2014, appraiser David Weiss, of Freeman’s, valued a high-quality copy of this print at $10,000 to $15,000 at auction.

Jasper Johns came of age in the post-war 1950s, a decade that has unjustly become a byword for placidity. A wild artistic movement called Abstract Expressionism was dispensing with the seemingly indispensible idea that a painting needed to depict an object. Abstract Expressionists painted color fields, dribbled paint across giant canvases, and sought to convey emotion without attempting to control it. The movement swept through Europe, pushed along by the United States’ sudden rise as a world power in the wake of World War II.

So it’s a very familiar image, but it doesn’t mean the same thing as the red-white-and-blue flags he’d painted before.

Simultaneously, the old European powers were failing, their post-colonial empires contracting and crumbling. France was forced out of French Indochina, a country we now know as Vietnam. Into the sudden vacuum of power came various Vietnamese factions, as well as agents of surrounding countries and of the new superpowers, the United States and the Soviet Union. In Washington, D.C., it became accepted truth that the Soviet Union, our old ally, intended to seize Vietnam and then conquer all of Southeast Asia. This could not be allowed to happen.

As the United States stumbled into a disordered war against two countries, the barely controlled frenzy of Abstract Expressionism became the common language of American fine art. Jasper Johns found he did not share the prevailing interest in disorder. He craved quiet, controlled canvases that concentrated their power as efficiently as possible. Like Marcel Duchamp had done, and as the Pop Artists would in decades to come, Johns found meaning in the familiar, and in objects so central to day-to-day life that they often went unnoticed. In 1954, according to a story Johns once told his friend Robert Rauschenberg, he had a dream in which he painted the American flag. When he woke up, he painted it; “Flag” was his first success. A few years later, he painted a cast-bronze sculpture of a coffee tin containing an artist’s brushes, “Painted Bronze." Was there a subtext, a message? Johns was not the kind of artist to offer an opinion. It was beautiful; it seemed necessary.

Rather than eschew meaning, as the Abstract Expressionists seemed to be doing, Johns had an instinct for the elemental, pre-rational power of symbols. Starting in 1955, he began producing his famous “Target” paintings, which defy description except to say that they are paintings of targets. What else can you say about a target except that it’s a target? You can describe it: concentric rings of alternating color. But you haven’t learned anything you didn’t know. Depicting “things the mind already knows,” Johns said, gave him “room to work on other levels.”

The war grew more costly, in lives and resources, through the 1960s, and more confused. America’s involvement had not grown in secret, exactly, but beneath public notice. It had become impossible to unearth the reason the United States went to Vietnam in the first place. (For a sense of the confusion, look at the paint-spattered chaos of a Jackson Pollock canvas. An anti-war left began to express opposition to the war, and grew in power. In 1968 Richard Nixon ran for president, promising to wind down the war.

Once elected, he enlarged it. As a corollary to his “Madman Theory” of war-craft, Nixon ordered the bombing of neighboring Cambodia. As he told his chief of staff, he wanted the North Vietnamese to fear him as a lunatic who would commit any atrocity to gain victory. In any case, the anti-war left was convinced.

In response to Nixon, the anti-war left began to organize a non-rational, symbolic response: multi-city marches and demonstrations, to be called the Moratorium Marches. Around the world, millions would participate, with half a million marching on Washington, D.C. Yet faced with such a massive chorus of rage and disapproval, Nixon effectively shrugged. “Under no circumstances,” he said, “will I be affected by [them].”

To raise money for the anti-war movement, a Los Angeles gallerist commissioned Jasper Johns to produce a poster. The war was, to the anti-war folk, so obviously corrupt; marshaling more arguments would be playing a rigged game. They didn’t need more thoughts. They needed a symbol that was so blatant that it was impossible to misunderstand, yet vague enough to lodge in the mind and irritate it. Hence, Johns produced a flag — another symbol so self-contained that it needed no definition — but unlike the red-white-and-blue flags he had painted a decade before, the Moratorium flag was distorted, sickly.

“Initially, it’s a patriotic image,” says David Weiss, “but we have these disquieting colors. Lurid green stripes seem to reference camouflage, the orange reminds you of Agent Orange. So it’s a very familiar image, but it doesn’t mean the same thing as the red-white-and-blue flags he’d painted before.”

There are very few stylistic differences between the Moratorium flag and Johns’ other flags, his targets, or his depictions of beer cans. Other than the color palette, they look the same. But in the context of the Vietnam War, Weiss says, it’s impossible to miss the point. The United States had become sick. It was no longer what it used to be.

The calamity of the Vietnam War brought out in Johns a specificity and directness that is not present in the rest of his paintings, which are populated by symbols so everyday as to evoke a sort of all-purpose meaningfulness. They do not generally arouse particular thoughts in the viewer’s mind — and Johns has no inclination to dissect his paintings and examine the sources of their symbolic power, a trait that is probably a precondition for being deft with symbols. “I don’t know how to organize thoughts,” he once told an English interviewer. “I don’t know how to have thoughts.”

In December 2007, a writer for Vanity Fair asked Johns, by then age 77, what his greatest regret was. “An absence of clarity,” he said. He responded to his own desires and pleased himself, but his deep motives remained mysterious to him. This uncertain terrain is the seat of an artist’s power. But at least in 1969, his message was clear. The war was wrong and it had to end.