This week marks the seventieth anniversary of the Battle of Leyte Gulf, where U.S. maritime forces reclaimed a beachhead in the Far East after being expelled in 1941-1942. In reality, Leyte Gulf was a series of naval engagements sprawling across the map of Southeast Asia. Three were centered on the gulf and its approaches, taking place in the San Bernardino Strait, the Surigao Strait and the waters off the island of Samar. A fourth pitted carrier fleets against each other in the open sea off Cape Engaño. Each ended in triumph for the U.S. Navy. The battle fulfilled General Douglas MacArthur’s vow to “return” to the Philippine Islands, but salving his wounded prestige was least among the fruits of victory. Victory conferred a host of operational and strategic benefits.

Just look at the map. Wresting the islands of Leyte and Luzon from Japan capped MacArthur’s island-hopping campaign, a string of consecutive amphibious operations that spanned the South Pacific. Luzon was the major prize. It lay athwart the sea routes that skirt north-south along the Asian seaboard. It also overshadowed east-west movement through the Luzon Strait, which connects the South China Sea with the Western Pacific. Capturing it fractured Japan’s innermost defense perimeter. The Battle of Leyte Gulf drove a stake into the empire, splitting off Tokyo’s Southeast Asian holdings from Japan proper. And it furnished U.S. commanders a launching pad for sea and air assaults against the Ryukyu Islands and the Japanese home islands.

In short, Leyte was a tactical action with strategic and political moment. Its dimensions were epic. As emeritus Naval War College professor George Baer points out, Leyte “was, in tonnage engaged and space covered, the greatest naval battle of all time.” Now any sea-power expert worth his salt—doubtless including Professor Baer—will tell you that tonnage and square miles are imperfect proxies for naval might. Firepower is another, arguably more reliable proxy. Partisans of Admiral Raymond A. Spruance use it to make the case that the Battle of the Philippine Sea, the mid-1944 invasion of the Mariana Islands that Spruance oversaw, qualifies as history’s greatest.

And it’s tough to gainsay such claims. Think about it. If size were everything, a fleet of mammoth container ships, some bulking half a million tons, would be today’s strongest navy. Tremble before the power of the Maersk Line! That, of course, is nonsensical. Spruance’s Fifth Fleet was indeed formidable in terms of concentrated striking power. In terms of operational results, moreover, the Philippine Sea covered the amphibious landings on Saipan, which from then on provided the Army Air Force an outpost to launch strategic bombing raids against Japan proper. Such strikes demolished Japanese naval aviation. Indeed, the fracas was so lopsided that American flyboys dubbed it the “Great Marianas Turkey Shoot.”

So debilitated was the Imperial Japanese Navy’s (IJN) flying corps after the encounter with Spruance’s carrier task forces that IJN flattops steamed out for Leyte Gulf virtually bare of pilots and planes. The force that had struck at Pearl Harbor with such skill and verve was reduced to a decoy, sent forth in hopes of luring American strength away from the Philippines.

Nor is a battle’s geographic sweep an infallible yardstick for its importance or results. If it were, that would imply that scattering forces hither and yon charts a route to strategic success. That may be, but more likely isn’t, a general rule. Carl von Clausewitz deems concentrating superior might at the decisive place and time the simplest and highest law of strategy. That could mean endeavors spanning a large area, but Clausewitz seems to envision a focal point where overpowering the foe makes all the difference. It’s hard to generalize. In short, ranking fleet actions against one another by metrics A, B, C or some combination of metrics is a dicey business.

But let’s leave the blood sport of ranking battles to historians. Baer also observes that Leyte was “the last great naval battle” of World War II. It broke the back of Japanese sea power, finishing what the Philippine Sea started. It forced the IJN into desperate—and increasingly futile—expedients in its bid to forestall defeat. No longer could Japanese mariners compete for mastery with any genuine hope of success.

Those are serious results. They affixed an exclamation point to what had gone before. As historian Samuel Eliot Morison recalls, logistics had already deranged Japan’s strategic position before Leyte. Fuel shortages compelled IJN commanders to disperse assets, thinning out the navy’s combat power   while accepting the danger of piecemeal defeat. Vice Admiral Takeo Kurita’s surface fleet had withdrawn to South China Sea anchorages to be close to its fuel supplies, while Admiral Jisaburō Ozawa’s aircraft carriers remained in Japan’s Inland Sea to train air groups to replace the ones devastated by repeated blows, most recently at the Philippine Sea.

Interposing U.S. forces at Luzon, where they could put the “cork in the bottle” of the South China Sea—to quote Admiral Ernest J. King’s evocative metaphor for Formosa—confirmed that the IJN would remain fragmented. Commanders couldn’t have it both ways. Surface task forces could stay in the “Southern Resource Area” and replenish their fuel tanks, or they could remain in Northeast Asia, close to supplies of ammunition, spare parts and stores. Picking among equally indispensable commodities represents an impossible choice for any sea service. Navies need all of them in lavish quantities to function.

What should posterity take away from the Battle of Leyte Gulf? For one thing, Leyte wasn’t just the last major fleet engagement of World War II. It was history’s last major fleet engagement—to date. Reflecting on it figures into the larger debate over whether the age of great-power conflict has drawn to a close, or whether history is simply taking a breather before resuming its bloody onward march. This isn’t the first time such a debate has taken place. Naval warfare paused for decades following the nineteenth century’s epochal fleet battle, the Battle of Trafalgar (1805). As any patriotic Briton of the day would have reminded you, Britannia ruled the waves for the rest of that century. (Boy, that must’ve gotten tiresome.) Imperial police actions, not combat against peer navies, constituted the rule of the day.

So is sea combat passé, or are the past seventy years simply a holiday from history? This is worth pondering. If navies no longer fight for maritime supremacy, why invest in aircraft carriers, guided-missile destroyers and other pricey hardware? Those carry heavy opportunity costs. Better to reconfigure navies for police duty, fielding swarms of small, lightly armed craft suitable for battling seaborne terrorists, lawbreakers of various stripes and weapons traffickers. If no future Leyte lies in store, navies should spare themselves—and taxpayers—the bother and expense of preparing for such a showdown.

For another thing, Leyte may be not just the biggest and last, but also the most thoroughly studied naval battle ever. It was a staple of the Naval War College operations curriculum when I was a student—a distressingly long time ago—and remains so to this day. And that’s right and fitting, so long as we attach an asterisk to our analytical pursuits. Strategic godfather Bernard Brodie warns against what specialists in logic term the “fallacy of composition.” Naval battles, confides Brodie, come along so seldom that it’s perilous to draw too confident conclusions from them. (We might add that they also come along too rarely to correct false lessons learned from past engagements, or to show when true lessons have been overtaken by new realities.)

We blunder, then, by reasoning from part of something to the whole—from trying to learn too much from too little information. Extrapolating from a single example is especially misleading. Shift a few minor variables—an unlucky break here, a loss of nerve by a commander there, a faulty tactical decision there—and the entire pattern of an engagement can shift. Historians and strategists could distill faulty lessons from reviewing battles whose outcomes were far from foreordained.

In other words, the sample size for them to review—the amount of data—is too small to allow analysts to generalize with any precision. It’s doubtful changing a few variables would have let Japan prevail at Leyte. The material mismatch yawned too wide after years of sanguinary combat. Yet the battle could have taken on a different cast—leading future generations to draw different, and perhaps wrong, conclusions from studying it.

And lastly, there are pitfalls to making historical events into legends. Leyte bears the hallmarks of a legend. If you doubt me, scope out James Hornfischer’s Last Stand of the Tin-Can Sailors. Few could read about the heroism of a Commander Ernest E. Evans who led the destroyer Johnston in a gallant—and successful, if also fatal—charge against Kurita’s battleship fleet off Samar, without a lump in the throat. Scholars and practitioners of sea power must guard against letting such tales color their appraisals of past events.

Leyte wouldn’t be the first legend to captivate subsequent generations to the detriment of wise strategy. Think about the Battle of Trafalgar (1805), where Lord Horatio Nelson’s outnumbered Royal Navy fleet vanquished a Franco-Spanish fleet near Gibraltar. Trafalgar swiftly took on sacral overtones. The clash even came complete with its own secular saint, Lord Nelson, who fell during the engagement. The historical Trafalgar soon degenerated into “Trafalgar,” a parable of naval strategy and derring-do whose lessons the Royal Navy old guard deemed beyond criticism.