What We Can Learn About a War in Asia Today from World War II

We don’t have to imagine how horrific a war in Asia between great powers would be. We need only look back to the inferno of World War II in the Pacific.

By Retired Admiral James Stavridis, Fletcher Dean Emeritus, and former supreme allied commander of NATO

The greatest sea battle in the long history of the oceans in terms of the total number of ships and sailors engaged was the epic Battle of Leyte Gulf, which occurred 80 years ago this month. The combined fleets of Japan and the United States brought 200,000 sailors, 400 warships, and 2,000 combat aircraft to a war fought in the waters off the east coast of the Philippines resulting in tens of thousands of casualties.

We talk a great deal these days about the possibility of a war with China. I am often asked whether we are already in a “cold war” with Beijing, and what are the chances of our robust basket of disagreements with China (Taiwan, cyber, trade and tariff disagreements, territorial disputes in the South China Sea) flashing into a hot war? It seems both unimaginable, yet all too possible.

But we don’t have to imagine just how horrific a war in Asia between great powers would be. We need only look back less than a century ago to the inferno of World War II in the Pacific. What lessons can we glean from a close look at the early 1940s, when the entire Pacific Ocean was seemingly on fire?

First, the geographic extent of the war in the Pacific was astonishing, covering close to half of the world’s surface. It stretched both at sea and ashore from the Hawaiian islands to the Philippines and central China, from the Aleutians in the high north to the northern coast of Australia. The war even extended into far southeast Asia and India. One image to hold in mind: You can take all the world’s land, and it will fit comfortably within the boundaries of the Pacific Ocean.

Similarly, a war between the United States and China would have an incredible geographic span, probably starting in the South China Sea—perhaps fueled by a Chinese attack on Taiwan—and spreading like a malignant tide rapidly across the vast land and sea space. The South China Sea alone is half the size of the continental United States. 

The likely range of combatant activities would include probable attacks on U.S. military reconnaissance and air defense systems in Alaska; an attempt to cut off logistic support from Darwin, Australia and Singapore; and potential attacks against strong U.S. allies in the region (Japan, South Korea, the Philippines). There would certainly be an element of the conflict occurring in space as well as both sides will try to knock out the satellite command and control and surveillance systems. Much as occurred in the 1940s, we will see a very geographically diverse conflict—even if we can somehow avoid an escalation to either the use of nuclear weapons or attacks on each other’s continental landmasses.

A second salient aspect of World War II in the Pacific was the remarkable acceleration of technology used in war. Among many other advances, both sides rapidly improved their cryptological and intelligence capabilities (perhaps the key advantage for the United States throughout much of the war was the impressive work and ingenuity of U.S. codebreakers). In addition, improvements in radar enabled new levels of night combat; sonar pierced the ocean’s surface to find and kill enemy submarines; torpedoes became far more lethal through better range and higher accuracy; and naval gunfire improved markedly through new computerized fire control systems.

But the biggest tactical breakthroughs surrounded the use of aircraft carriers. As the war progressed, these “bird farms” became the apex predators of the war, far surpassing the lethality of the battleships that were regarded as the heart of the navy battle line in the prewar years. In the opening salvo of World War II, the Imperial Japanese Navy’s surprise attack at Pearl Harbor destroyed the U.S. battleships. Luckily for the Americans, the carriers were at sea on that fateful Sunday morning, sparing them to fight the early battles of Coral Sea and Midway. 

By the time of the sweeping battles of the Marianas and Leyte Gulf in 1944, as the Americans were storming back across the Pacific, new, larger carriers with far better aircraft—the new Essex-class carriers and heavier Hellcat aircraft with self-sealing fuel tanks—took to the sea. And the admirals were learning how to use the new carrier capability—Spruance, Halsey, and Mitscher, under the steady leadership of Nimitz—piled innovation upon innovation in using the carriers. In fact, the vaunted battleships ended up being a sideshow in the war, with the two Japanese super battleships—at 70,000 tons each the largest warships in the theater—being ignominiously sunk without inflicting any damage on the U.S. fleet.

Toward the end of the war, the Japanese introduced yet another innovation, albeit a grisly one: the use of kamikazes, the “divine wind” attacks, employing largely untrained pilots ordered to simply fly their fueled and armed aircraft into U.S. warships. Totally unexpected, this tactic cost the United States thousands of lives and dozens of warships, all lost to what in some senses equate to drone warfare today. After all, once you decide the life of the pilot is irrelevant, your aircraft effectively becomes an unmanned but highly guided projectile with deadly effect.

Finally, the largest World War II innovation, the one that ultimately has since most affected global geopolitics, was the invention and use of the nuclear bomb. By winning the race with Hitler’s Germany to acquire nuclear weapons, the United States was able to end the war quickly, saving millions more lives after the tragic destruction of Hiroshima and Nagasaki. It was a dramatic new technology that upended the conclusion of the war in a sudden deus ex machina.

In a modern-day war with China, we need to expect a highly innovative approach in terms of both technology and tactics. The People’s Liberation Army Navy (PLAN) has shown itself capable of adapting to U.S. technology and tactics, including pursuing both conventional and nuclear-powered carriers; building advanced drones both for surveillance and strike; fielding highly sophisticated offensive cyber capability; developing quieter submarines (both conventional diesel and advanced nuclear-powered attack boats) and fielding a growing nuclear arsenal (both strategic and tactical). 

They are also exercising frequently at sea with Russia (including in the Arctic and Baltic Seas) and sharing advanced technologies and training techniques. In a great power war in the Pacific, we will see a great deal of innovation. All of this would undoubtedly accelerate in the event of a great power war, just as it did in the 1940s.

A third aspect of war with China, unfortunately, will probably be a very high level of casualties. We have come to think of war as a kind of precise, Tom Clancy–like battle between robotic unmanned systems, valiant special forces commandos, and swift cyber-attacks; and there will certainly be some of that. But war will still likely have high human cost alongside all the new technology.

After all, the war in Ukraine novelistically is a cross between Erich Remarque’s All Quiet on the Western Front, the muddy and brutal battles of World War I; and Robert Heinlein’s futuristic tale Starship Troopers. A war between the United States and China would almost certainly have elements of both. In the Pacific during World War II, close to 35 million people were killed, the vast majority of them civilians. A great power conflict may cost multiples of that, even if we can avoid the apocalypse of a major nuclear exchanges.

Above all, the most obvious and important lesson we can learn is to avoid such a war to begin with. All wars come at immense individual human cost. It was never inevitable that the United States and Japan would end up in a war in 1941, but ultimately both sides failed to find a diplomatic path to ease the economic tensions facing Tokyo attendant to a decade of their brutal conquests throughout Asia. When war came, starting with the attack on Pearl Harbor, the result was sweeping catastrophe that rewrote the future of Japan, catalyzed the creation of many new combat (and eventually civilian) technologies, and killed millions.

As we think about the legacy of the Battle of Leyte Gulf, it seems unlikely we will ever see again two such massive battle fleets go toe-to-toe in the relatively confined waters of a place such as the western Philippine Sea. But the lessons of that deadly inferno can help us prepare for such an eventuality, and reinforce the importance of creating a combination of robust deterrence, integrated alliance systems, and clever diplomacy to avoid yet another devastating war in the Pacific.

(This post is republished from U.S. Naval Institute.)