This week, theaters across the world will show Dunkirk, a motion picture about one of the most unlikely and incredible series of events in the history of modern warfare. Although well-known in Britain, many in the United States and elsewhere will learn about the remarkable nine-day-long retreat and evacuation for the first time.

Joshua Levine, author of the 2010 book Forgotten Voices of Dunkirk, served as the film’s historical advisor and, just in time for the movie’s release, has prepared a companion volume, Dunkirk: The History Behind the Motion Picture. Both book and movie will suit anyone interested in military history from the soldier’s point of view. They also tell us something important about what makes Britain Britain.

Fight for Survival

The Second World War began quickly in the East, as German forces smashed through Polish defenses. In the West, the story was different. British, French, and Belgian troops stared across the lines at their fascist counterparts in an eight-month standoff that came to be known as the “Phoney War.” In May 1940, that ended as the Germans unleashed their blitzkrieg upon the western powers.

The German attack sent the allied forces reeling as an invasion of the Low Countries coupled with a devastating assault through the Ardennes ripped holes in the defensive lines, making the fall of Paris, and all France, not only possible but imminent. The British Expeditionary Force (BEF) was not the focus of the attack, but found themselves in headlong retreat nonetheless so as to avoid encirclement and capture by the Germans.

The Phoney War was over, replaced with a terrifying fight for survival. After British plans for a counterattack were abandoned as impracticable, the strategy shifted from defeating the enemy to avoiding complete annihilation of the British Army. “Survival,” one soldier is quoted as saying, “was the main object in everybody’s mind.”

As Levine notes, director Christopher Nolan reflects this shift in the film by barely showing German soldiers at all, focusing instead on the confusion on the beaches as hundreds of thousands of allied troops were forced to retreat within an ever-shrinking perimeter of relative safety. For those who leave the movie wishing for more information about the enemy’s movements and the political maneuverings behind the lines, the book is a good resource in filling in those gaps.

“Relative safety” is the right word for the beaches, as Levine describes in detail the tales of men who, even after they extract themselves from the front lines are helpless against German aerial raids on the crowded shore. Here is where Levine’s contact with surviving veterans is most important, as the real stories of the men who were there bring the history to life on the page.

Unlikely Armada

With the German forces ten miles from the beach, Prime Minister Winston Churchill and his cabinet set about devising an evacuation, but their expectations were low: Churchill believed they might get 30,000 men off the beach, less than ten percent of the total. Regardless of the odds, they knew it was imperative to try, an early indication of the implacable resolve that would characterize the British people from then until the tide of the war turned in their favor years later.

Evacuation required every seaworthy ship the British Navy could lay its hands on, and was complicated by the lack of a deep harbor at Dunkirk. Soldiers would have to walk to the end of a long breakwater that extended into the channel, climbing from there to a small vessel that would ferry them to a larger naval ship farther out to sea. The operation was tenuous, and was all the while imperiled by frequent German air attacks and naval mines that peppered the sea lanes.

Civilian ships from around Britain were pressed into service, venturing into an environment that they and their crews had never contemplated. Despite the best efforts, the going was slow; only 7,669 soldiers had been brought home. As the situation grew direr, the men in charge gradually improved at their task, and by the fourth day they had exceeded Churchill’s estimate. Over the next week, the total grew to greater than anyone could have hoped, with 338,000 being rescued, a number that included many French and Belgian troops who had gotten mixed in with the BEF.

The Dunkirk Spirit

None of it would have been possible without the order amid disorder that seems, then as now, to be the epitome of Britishness. There were some men who, driven by fear, tried to jump the lines or overload the small vessels. There was some degradation of the social order: As uniforms frayed and organization degraded, some of the differences of rank went with them. But for the most part, the men queued up, pulled together, and followed the rules.

Episodes of shocking orderliness fill the book. One officer boarded a boat that had, until recently, operated as a civilian ferry in the Irish Sea. Once underway, he asked a steward for a class of beer. The steward refused, politely informing him that the rules required alcohol not be served until the ship was three miles out from land. To a man who had stepped over dead bodies to board the ship, enforcing the rule seemed ridiculous, but also delightful. “How could we lose the war,” he said in recounting the story to Levine, “with people like this around.” Regulation in the midst of chaos became the order of the day until the war was won, and nothing could be more quintessentially British.

The Dunkirk evacuation had all the hallmarks of what normally would be considered a defeat. But the British turned that on its head, emotionally, if not tactically. Men returning to England from the beaches of Dunkirk expected to be shunned for their failure; instead, they were celebrated for their courage and pluck. Britain hungered for victory, but still embraced their defeated soldiers. The attitude then and throughout the war was that they would take their lumps and mourn their dead, but that they would never give up. Churchill’s famous speech that followed the end of the evacuation summed up what came to be known as the “Dunkirk spirit”:

We shall go on to the end. We shall fight in France, we shall fight on the seas and oceans, we shall fight with growing confidence and growing strength in the air, we shall defend our island, whatever the cost may be. We shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender, and if, which I do not for a moment believe, this island or a large part of it were subjugated and starving, then our Empire beyond the seas, armed and guarded by the British Fleet, would carry on the struggle, until, in God’s good time, the New World, with all its power and might, steps forth to the rescue and the liberation of the old.

Churchill spoke for Britain, and eventually for the whole free world, in what he said that day. Today, the threat of terror in Britain and throughout the West threatens in ways that, like the Nazi threat, are terrifying. Jihad has not yet, and likely never will, claim so many lives as fascism. The threat from knife-wielding assailants, as we saw last month in the London Bridge terror attack, is real and dangerous, even if it is little compared to the Blitz.

Even so, something of that spirit of Dunkirk has wended its way into Britons’ DNA. Whether it be in the man fleeing the jihadis while not spilling a drop of his beer, or the man who, confronted with the terrorists’ cries of allegiance to Allah, replied with his own fealty to a third-tier soccer team (while being stabbed for his trouble), the British desire to persevere, to keep themselves together, and ultimately to win was alive that night. That it should be so is owed, in part, to what happened at Dunkirk in 1940.