As the United States and Britain prepare to go to war against a madman, it is wise to remember another time when much of the world was in crisis, a time when people everywhere also eyed with deep suspicion a dark-moustached dictator who appeared bent on terror, death and dominion.
Fully three years prior to his 1939 invasion of Poland, Adolf Hitler had sent planes, tanks and troops into Spain in support of the Spanish generals, led by Francisco Franco, who were attempting to overthrow that country's popularly elected government. In January 1937, Hitler personally had warned the citizens of Spain's Basque region that they should end their resistance to the generals or face annihilation. Then, on 26 April of that year, in the late afternoon of a busy market day in the town of Guernica - home of the sacred oak tree beneath which Basque leaders and Castilian monarchs had sworn for centuries to uphold democratic rights - Hitler's Luftwaffe began a relentless bombing and machine-gunning of businesses, homes and innocent inhabitants. Three and a half hours later, the village lay in ruin, its population decimated.
Hitler's act of terror and unspeakable cruelty - the first intentional, large-scale attack against a non-military target in modern warfare - outraged hundreds of thousands of people who previously had simply observed the machinations of the German leader with apprehension. Immediate condemnations were expressed around the world, yet not a single government was moved to change its policies toward Germany or come to the aid of the embattled Spanish Republic. The boldest reaction to the bombing, in fact, came when Pablo Picasso, at that time a Spanish expatriate living in Paris, responded with artistic fury. Reacting almost immediately to the devastation in his homeland, he began work on a massive canvas that would become his testament in opposition to the horrors of war, a mural that is widely regarded as the most important artwork of the bloody 20th century.
Although Picasso had read numerous newspaper accounts detailing the destruction of Guernica, not once did he experiment with images of airplanes, bombs or exploding buildings as he began to sketch. He had not been truly interested in any sort of visual documentation since before the turn of the century, regardless of its subject. More importantly, Picasso found himself interested not so much in what the bombing and burning of Guernica meant politically, but rather what they meant in metaphor, what they meant in the context of individual human lives. He wanted to address emotively the destruction of his beloved country, and he already possessed a personal visual language with which to do so, one anchored in the violence, suffering, and passion of the bullring, as well as in the centuries-old Spanish belief in the essential tragedy of life, one embodied by the fig-ure of a grieving woman, La Llorona.
Guernica's visual imagery - a screaming horse which had fallen, pierced by a lance; a wailing woman holding a dead child in her arms; another woman, her clothes on fire, attempting to escape from a burning building; the severed head of a soldier - spoke not specifically to a terrible day in Spain. Rather, it spoke to the horrors that humans have visited on each other for millennia, and because of this the painting began to symbolise the reality of every war remarkably soon after its creation. And in the ensuing half-century, Guernica has become for people around the world visceral, visual evidence of the true nature of war, a perspective very unlike the heroic and optimistic one so often presented by politicians who have never seen war close at hand.
I was in Madrid on 11 September 2001, observing Guernica and researching its history for a book, when, across the Atlantic - and as had occurred in the town of Guernica 64 years before - the city of New York fell under an utterly new kind of warfare. In both instances, the targets were symbolic; the aim of both attacks was to incite terror from out of the otherwise sheltering sky, and to destroy thousands of people who had no idea of their supposed crimes. In New York, as had happened long ago in Guernica, barbarity and senselessness took hold.
In the following days, people throughout Spain drew my attention to the similarities between the two attacks, and in the town of Guernica, a soft-spoken city attorney observed: "Although we have no skyscrapers in Guernica, now we are a brother city to New York." The outpouring of grief in Spain over the 11 September attacks was widespread and deeply moving. Yet, in only a year, that compassion over the loss of innocent American lives has been largely replaced in the Basque country and the rest of Spain - indeed, throughout much of the world - by huge apprehension about the naivety of America's anti-terrorism goals and its cowboy approach to achieving them. And the painting Guernica, long a potent symbol of opposition to war and violence around the globe, already seems less immediately reflective of that unimaginable morning in New York little more than year ago than it is of what soon may occur in Iraq.
In the aftermath of 11 September, and in his prickly, lone-eagle impatience with the UN's global approach to disarming Saddam Hussein, George W Bush leads a US administration that appears to observers in other nations to be belligerent, utterly uninterested in dissenting perspectives and determined to make war at any price. Further emboldened by the steadfast support of Tony Blair, it may be that as Bush plans for a pre-emptive war against Iraq he has carefully considered the different course history might have taken if Hitler had been stopped 65 years ago as he entered Spain and fought to destroy democracy.
Yet if Bush does see a correlation, he misses a vital point: a bold strike against Hitler in 1937 - something that very arguably should have occurred - would have been made in response to his incursion into Spain and his slaughter of thousands of innocent civilians and not on the possibility that he was about to do so. It remains very difficult to imagine that any nation in the world would have sanctioned a military strike against Hitler that year, if his troops, tanks and planes had remained inside Germany's own borders, and the town of Guernica had continued to stand. Yes, the Nazis were amassing sophisticated new weaponry at a very alarming pace - precisely what Saddam Hussein is accused of doing today - but the decision to go to war before one's enemies do is the thinking of despots, not statesmen.
Pablo Picasso was outraged by what he watched happen to his homeland from distant Paris. And although he despised Franco and Hitler, his masterpiece includes no imagery indicting either man for the destruction of Guernica. He understood - as contemporary leaders apparently fail to do - that the fundamental reality of war is not strategic positioning, the stockpiling of weaponry, the righting of previous wrongs or even the quest for oil, but is rather the terrible, wanton and tragic destruction of human life.
Sixty-five years after it was created, Picasso's great and powerful painting reminds us of critical truths that the western powers ignore at their peril: that war is hell on earth; that the decision to go to war in the name of principle, policy, or even defence is always a very grave one; that free and just peoples are never the first to strike.
Russell Martin's Picasso's War: the extraordinary story of an artist, an atrocity - and a painting that shook the world is published this month by Scribner (£18.99)