Against British naval superiority, America managed a few striking victories. Art by Thomas Birch, “Engagement Between The ‘Constitution’ and the ‘Guerriere’ ” (1813) / Granger Collection

Can history explain anything? Henry Adams, after a lifetime of writing about American history, wasn’t sure that it could. “Historians undertake to arrange sequences,—called stories, or histories,—assuming in silence a relation of cause and effect,” he wrote. But he suspected that the assumptions wouldn’t bear scrutiny, and he was haunted by the idea that hoping for a causal explanation of human affairs might be a mistake. “Chaos was the law of nature,” he suggested late in life. “Order was the dream of man.”

Perhaps it was Adams’s penchant for historiographic nihilism that drew him to the War of 1812, the conflict with Britain that looms over his masterpiece, the nine-volume “History of the United States During the Administrations of Thomas Jefferson and James Madison.” As a great evil, a war calls out for some kind of theodicy—for an explanation of why it happened and what it meant—but the War of 1812 frustrates the desire for such answers. Its origins lie in a concatenation of misperceptions, crossed signals, and false hopes. Its end is no less obscure: America, which started the war, accomplished none of its stated aims, and the peace treaty merely restored the combatants to the status quo before the fight. A number of historians feel that neither Britain nor America won—though most agree that the Indians, allies of Britain who never again seriously obstructed white America’s expansion, definitely lost. At the time, no one seemed to have more than a partial understanding of why they were fighting. A British government official compared the two countries to two men holding their heads in buckets of water, to see who would drown first. Adams wrote of the first winter of the war, “So complicated and so historical had the causes of war become that no one even in America could explain or understand them.”

Many of Adams’s successors have found it just as hard to say what the war was about. Recently, in “The Civil War of 1812” (Knopf; 2010), Alan Taylor pushed pointillism even further than Adams did, taking as his subject the unstable allegiances and local vendettas along the border between America and Britain’s Canadian colonies—the sort of fractal details that tend to get smoothed out of popular narrative. “No single cause can explain the declaration of war,” he wrote. In “The Weight of Vengeance” (Oxford), a new study marking the war’s bicentennial year, Troy Bickham repeats the refrain: “There is no single explanation for the outbreak of war in June 1812.” But Bickham has a trick up his sleeve. It turns out that he’s an optimist. He thinks that it is possible to say what the war was about. What’s more, he’s sure that Britain lost.

Within America, the War of 1812 was controversial—advocated by Republicans, who were known for their hatred of taxes and big government, and opposed by Federalists, who favored élite rule, central banking, and a peacetime defense establishment. Donald R. Hickey, a Wayne State College historian and the dean of 1812 scholarship, has called the vote to declare war the closest in American history. “Many nations have gone to war in pure gayety of heart,” Adams wrote, “but perhaps the United States were first to force themselves into a war they dreaded, in the hope that the war itself might create the spirit they lacked.”

The slogan of the so-called War Hawks centered on two issues: “free trade and sailors’ rights.” By “sailors’ rights,” they meant an end to the British practice of conscripting, or impressing, sailors from American merchant ships. By 1812, between nine and twenty thousand British sailors were working aboard American vessels, which paid more than twice as well as the Royal Navy. Britain, at war with France for nearly two decades, didn’t think it could afford not to go after them. The American government considered many to be naturalized citizens, but British law deemed allegiance to the King indissoluble, and, at the time, it wasn’t easy to tell an American from a Briton even if you agreed on the definitions. Though the American government issued certificates of citizenship, they were so easily forged that few British captains respected them. Many sailors simply identified themselves with tattoos of American flags or eagles. Under the circumstances, Taylor writes, “every British impressment was an act of counterrevolution.” Secretary of State James Monroe counted more than sixty-two hundred impressments of American sailors between 1803 and 1811.

What about the “free trade” half of the slogan? British planters in the West Indies blamed American shippers for a sugar and coffee glut that was eroding prices in Europe, and they called for a crackdown on America’s profitable trade with France and the French West Indies. Intermittently, the British government tried to regulate the United States almost as if it were still a colony. In 1807, in response to an attempt by Napoleon to blockade its coast, Britain issued a series of decrees, known as Orders in Council, that required American ships to dock in a British port and pay a British tax before trading with any part of Europe under Napoleon’s control. As Adams put it, “American commerce was made English.”

Yet neither free trade nor sailors’ rights fully explains the outbreak of war. Impressment had been going on for years before Republicans started to harp on it, in late 1811. Even though the dispute had, in 1807, provoked a British warship to fire on an American one, no less an authority than Thomas Jefferson said he hoped that the two nations “might have shoved along.” In addition, war was bound to put a stop to commercial shipping, sending the very sailors whom America was trying to protect back to the Royal Navy in search of employment. Impressment hardly seems decisive when, Bickham points out, war continued even after the issue became moot, in the spring of 1814, when Napoleon fell from power and the Royal Navy began discharging sailors instead of recruiting them. As for free trade, America didn’t go to war until five years after the Orders in Council; instead, it tried what Jefferson called “peaceable coercion,” a series of obstacles to trade with Britain. And France behaved at least as badly, seizing American ships bound for or leaving Britain. “The Devil himself could not tell which government, England or France, is the most wicked,” a North Carolina congressman remarked. What’s more, America’s peaceable coercion of Britain eventually succeeded, thanks to an assist from Napoleon’s blockade and an economic depression: in 1811, high bread prices caused riots in England, and by the end of the year the mills of Manchester lacked cotton. Eventually, on June 16, 1812, Britain announced the rescinding of the Orders in Council. But the news didn’t reach America for five weeks, and two days after Britain’s announcement the United States declared war. President James Madison later admitted that he would have delayed the declaration if he had known about the repeal. British merchants were so confident that war had been forestalled that they rashly celebrated by sending the White House a large quantity of English cheese.

Still, Bickham insists that the war was “no accident,” and, indeed, British and American attempts to reach an armistice failed in August of that year, as did Russian offers to mediate, in 1813. In Bickham’s opinion, the war continued after the evaporation of its ostensible causes because a larger issue was at stake: “whether or not the United States would be respected as a sovereign nation.” Bickham writes that Britain “sought to stifle American ambition and turn it into a client state,” which implies that Americans confusedly but accurately diagnosed a threat to their interests. But if a historian, looking at the matter in retrospect, isn’t able to say exactly which interests the war protected, it seems just as likely that Americans were acting against their interests. Must the war mean what early Americans say?