A Measureless Peril: America in the Fight for the Atlantic, the Longest Battle of World War II

Of all the threats that faced his country in World War II, Winston Churchill said, just one really scared him—what he called the "measureless peril" of the German U-boat campaign.

In that global conflagration, only one battle—the struggle for the Atlantic—lasted from the very first hours of the conflict to its final day. Hitler knew that victory depended on controlling the sea-lanes where American food and fuel and weapons flowed to the Allies. At the start, U-boats patrolled a few miles off the eastern seaboard, savagely attacking scores of defenseless passenger ships and merchant vessels while hastily converted American cabin cruisers and fishing boats vainly tried to stop them. Before long, though, the United States was ramping up what would be the greatest production of naval vessels the world had ever known.

Then the battle became a thrilling cat-and-mouse game between the quickly built U.S. warships and the ever-more cunning and lethal U-boats. The historian Richard Snow captures all the drama of the merciless contest at every level, from the doomed sailors on an American freighter defying a German cruiser, to the amazing Allied attempts to break the German naval codes, to Winston Churchill pressing Franklin Roosevelt to join the war months before Pearl Harbor (and FDR’s shrewd attempts to fight the battle alongside Britain while still appearing to keep out of it).

Inspired by the collection of letters that his father sent his mother from the destroyer escort he served aboard, Snow brings to life the longest continuous battle in modern times.

 With its vibrant prose and fast-paced action, A Measureless Peril is an immensely satisfying account that belongs on the small shelf of the finest histories ever written about World War II.

“What’s the Matter with the Davis?”

Looking back on the Atlantic struggle

One hot, windy September afternoon in the early 1970s my mother and father came home to Bronxville from a two-week vacation in Maine. Bronxville is a town in Westchester County, half an hour north of Manhattan on what was then the Penn Central railroad. Like countless thousands of other couples, my mother, Emma, and my father, Richard, had quit the city in the hopeful months after World War II ended to raise their infant child in a house surrounded by suburban greenery and well-nourished public schools.

The beneficiary of this relocation came down to help them unload their luggage, and I was soon joined by Mr. Curcio, the superintendent of the apartment building in the village my parents had moved into after I’d gotten out of college.

Superintendent Curcio was a chatty, affable, powerfully built man (he once paused halfway up a flight of stairs to speculate with me at some length about the Mets’ chances, all the time holding two air conditioners, one under each arm). He scooped a half dozen suitcases out of the Chrysler, and as we headed toward the apartment, something—the weather, perhaps—reminded him of having taken part in the landings on Sicily in July 1943, and he began to talk about it.

“Look, I’m a wop,” he said cheerfully about his Italian heritage, “but let me tell you, once those wops on the beach were shooting at me, I was one hundred percent American. Guys begin dropping around me, and I start firing while I’m still in the water.”

The story continued until the suitcases were in front of the door. We all said thanks, and then my mother put a protective hand on my father’s forearm. “I’m so glad,” she told Mr. Curcio, “that Dick was never in action.”

AT A LITTLE AFTER eight thirty on the morning of April 24, 1945, a sailor said to my father, “What’s the matter with the Davis?” He meant the Frederick C. Davis, destroyer escort 136, and she looked funny, canted forward and apparently stopped in the water. My father was watching her from the deck of another destroyer escort, the USS Neunzer, DE-150. The Davis lay a few hundred yards away, but not for long. “Jesus Christ!” said someone. “She took a fish.” And sure enough, although nobody aboard the Neunzer had heard the explosion, a torpedo had struck the Davis’s forward engine room. Minutes later the Davis split apart and sank, taking 115 men to their deaths, while the Neunzer and seven other destroyer escorts—helped by planes from the escort carrier Bogue—set off on what would prove to be a ten-hour struggle against the submarine that had destroyed her.

While he unpacked in Bronxville, my father reviewed his role in this event for my mother, then added, with what seemed to me impressive mildness, “That’s generally considered having been in action.”

MY FATHER TOOK PART in the last great campaign of the Atlantic war. The Neunzer was one of a web of ships stretched across a hundred miles hunting an enemy that naval intelligence had reason to believe was going to launch rocket attacks against American cities. He was in at the end of the longest battle of World War II, indeed, of any war in history. If the Allies had lost that battle, they would have lost the war.

And yet, my mother’s remark was not ludicrous.

Few people today remember the Atlantic war as a battle, and even at the time only some of those who were in it saw it as a coherent effort. The Pacific was the picturesque war, the one where naval victories took the form we think they should: battleships hammering it out gun to gun, aircraft carriers deciding in a morning the fate of nations. Louis Auchincloss, already a lawyer, soon to be a novelist, but at the time the navigator on an LST (landing ship, tank) remembered, “Changing oceans was like changing navies. In the European theater the army and air force were everything; the navy, only a police escort. . . . Never shall I forget my first glimpse of the Pacific navy in the atoll Ulithi where the lines of battleships, cruisers, carriers, and auxiliary vessels seemed to stretch out to the crack of doom.”

Conquer an island; then conquer another island; then sink some battleships. That was a proper sea war. The Atlantic effort by contrast was strange and diffuse, week upon week of boredom endured in constant discomfort, fires on the sea at night and yet nothing there in the morning, eventually the unheroic sight of Halifax through the fog if you were lucky. It was a sea fight whose results were recorded on land. But it began on the first day of the war and ended on the final one, five years and eight months later. In the Pacific, the Battle of Midway broke a Japanese fleet in five minutes.

But the Allied aim in the Atlantic was not to destroy an enemy on the high seas. It was to keep a delivery system going: to get grain and aviation gas, chocolate and rifles and tires, oil and boots and airplane engines, from America to Europe. The trucks in this operation were merchant ships, some of them ancient, none of them carrying the martial glamour of a PT boat, let alone a cruiser.

One who did see the high consequence of this dogged chore was Winston Churchill. He said that the U-boat campaign was “the only thing that ever really frightened me during the war.” While the Atlantic battle was going on, he wrote, “How willingly would I have exchanged a full-scale invasion for this shapeless, measureless peril, expressed in charts, curves, and statistics.” The charts and statistics showed how many ships the German submarines were sinking, as against how many the Allies could build. It was “a war of groping and drowning, of ambuscade and stratagem,” said Churchill, “of science and seamanship.” If the stratagems failed, if the seamanship faltered, Britain would starve and the European fighting fronts would fall to the German army.

In Commander in Chief, his fine book about the American high command in the war, the historian Eric Larrabee wrote the arresting sentence “The Battle of the Atlantic was the war’s inner core, an only partly visible axle on which other contingencies turned.” That image has stayed with me since I first read it twenty years ago, although I can also see the battle as a vast drill bit or screw, with grooves a week or a month apart, turning and turning through the mortal years, always from America toward Europe, driving convoys eastward. Some of the vessels it carries will get through fifty trips without a scratch; some will burn and sink in front of vacationers on Miami Beach. Sometimes destroyers will protect them; sometimes there won’t be enough destroyers to spare for the job; and sometimes the destroyers won’t do any good at all, darting this way and that as the U-boats lance into the heart of the convoy and with a torpedo or two turn the months of manufacturing the ammunition and trucks and locomotives and radios and the days of loading them and all the time spent building the vessel that carries this cargo and the lifetimes of raising the crewmen who are attending it into a horrible inanity.

The battle killed nearly eighty thousand people: drowned them, crushed them, burned them, froze them, starved them in lifeboats. Far beyond the brutal vacancy of ocean that extinguished all those lives, an empire of strenuous ingenuity fizzed and crackled, whole cities running night and day given over to trying to outsmart the slim, dark shapes that Allied seamen so rarely saw.

It took three nations to end the U-boat campaign—the...