LIKE ALMOST ALL THE CIVILIAN ARCHITECTS of our war in Iraq, including the president, vice president, and Secretary of Defense, everything I know about actual combat I learned secondhand. I once sat in a tiny Pentagon office with the late, legendary Colonel John Boyd, a fighter pilot who was considered the most brilliant military theorist of our time, and listened to him expound on arcane-sounding “OODA loops,” a strategy for outmaneuvering our enemies that was instrumental in crushing Saddam Hussein’s armies in both Iraq wars. But most of what I know about war I learned from a former Navy lieutenant named Charles L. Ennis. He was my father, and I really didn’t understand some of his most important lessons until he died a few months ago.

My father left behind a brief, typewritten autobiography, a familiar Greatest Generation tale of a kid who grows up during the Great Depression (at the worst of it, he and his family lived off the land in the Northern California wilderness) and then goes off to global war, in his case aboard an aging destroyer-minesweeper that island-hopped from Guadalcanal to Palau before it was finally blown in two. Rescued from the sea, my father was soon shipped out on another destroyer-minesweeper, the U.S.S. Butler. And here his tale begins to read a bit like Joseph Conrad’s Heart of Darkness.

The first ominous hint as to what waited at the end of the voyage was the anti-aircraft drills, repeated far beyond the proficiency necessary for a minesweeper’s crew. Then there was the officer’s club at Pearl Harbor, where an encounter with an old college chum introduced him to a word few Americans in or out of uniform had ever heard: “kamikaze.” Rumors of the Japanese suicide planes haunted the Butler’s crew as she steamed toward the island of Okinawa, several hundred miles south of the Japanese home islands, where the largest amphibious invasion force of the Pacific war had gathered for the greatest land, sea, and air battle in history.

The first massed suicide attacks came several days after 60,000 American soldiers stormed ashore, the kamikazes coming in waves of hundreds of aircraft, formations their doomed pilots called “floating chrysanthemums.” In my father’s account, the horror inexorably escalates: the first attacks seen at a distance; the swarms of suicide planes “like gnats in the evening sky”; the first appearance of piloted, rocket-powered baka bombs, launched from Japanese bombers; the eating and fitfully sleeping at around-the-clock battle stations for two months straight, the sense of doom ever more pervasive; the rotting bodies of American sailors floating uncollected in the sea around them. My father’s radioman, standing at his side, has most of his head blown off in a spray of hot shrapnel as four kamikazes, one after another, are splashed within yards of their target. By the time the Butler’s end comes in a huge explosion, it seems inevitable. Five thousand American sailors died at Okinawa, the deadliest battle in the history of our Navy. The carnage was just as hellish on land, where eight thousand American soldiers died and more combatants were put out of action by psychological stress than in any campaign our nation has ever fought.

I often think about my father and the lessons of Okinawa as we endure another summer of our discontent in Iraq, the “central front” in our present-day global war, the war on terror. At Okinawa my dad was one of the first Americans to experience what we refer to now as asymmetric war, the use of often shockingly unorthodox weapons and tactics to get the drop on a more powerful opponent. In its most basic form, it’s puny but cagey David versus overgrown Goliath. The Japanese had actually started the war with an edge in power in the Pacific, and in December 1941 they had attacked all over the Pacific and East Asia with superior air, sea, and ground forces. But we had the inherent advantage once our manpower and factories were mobilized and the Japanese empire had slowly collapsed, its ships and planes eventually becoming sitting ducks for our huge new naval armada, its armies dug into desperate defensive positions. Asymmetric suicide attacks were its last grisly hope.

The current global war, by contrast, started out asymmetrical, when Osama bin Laden, whom we had previously aided in his own asymmetric war against the Soviets in Afghanistan, turned the tables on us. The Bush administration, though obviously not prepared for bin Laden’s September 11 suicide attacks, had actually anticipated the war that would follow. Secretary of Defense Donald Rumsfeld came into office with the president’s urgent mandate to transform a military built for set-piece, symmetrical combat against the Soviet Union into a more mobile, improvisational force ready for asymmetrical war. The rout of the Taliban in the months after 9/11 was a triumph of Pentagon new-think, with U.S. Special Forces on horseback calling in strike aircraft armed with laser-guided precision bombs.

Iraq seemed to offer Rumsfeld an even better demonstration of how fast a relatively small, highly mobile, electronically networked invasion force could take down a plodding foe like Saddam Hussein’s Soviet-style army. The victory over Saddam’s sad-sack troops was even more smashing than Rumsfeld had hoped, but like the whipped Japanese at the end of World War II, Saddam went asymmetrical, unleashing tens of thousands of young political thugs and mercenaries known as the Saddam Fedayeen even as he disappeared into his spider hole.

The Fedayeen-led insurgency picked up steam as Saddam’s former Baath party cronies, many of them jobless after we disbanded the Iraqi army, joined up along with a few thousand foreign fighters. Soon more Americans were dying in the peace than in the war, and what had started as a dazzling display of our own asymmetric war capabilities had turned into an asymmetry gap. But when alerted to the swarming Fedayeen as early as the first week of the war, Rumsfeld dismissed them as inconsequential “dead-enders.” By contrast, after the first WWII kamikaze attacks, the Navy brass moved quickly to adapt their weapons and their training. So consider this Okinawa lesson number one: Don’t get so enamored of your game plan that you don’t notice when the other guy changes his. It’s often when he’s losing—and according to the Bush administration, the Iraqi insurgency has been losing for more than three years—that he’s at his most dangerous.

However, once the administration had finally accepted that the dead-enders might be around for a while, it was deft in putting a face on the insurgency. Former Secretary of State Colin Powell mentioned Abu Musab al-Zarqawi twenty times in his infamous February 2003 speech presenting the United Nations all the reasons why Saddam had to be stopped; among the evidence that we later had to back away from was the certainty that Zarqawi, who had set up a training camp in Kurdish-controlled northern Iraq, was a bin Laden associate. This fiction became a self-fulfilling prophecy when a year later Zarqawi, who had previously feuded with bin Laden, swore loyalty to him and renamed his operation Al Qaeda in Mesopotamia. In many ways we were Zarqawi’s publicists as he rose to terror superstardom, President Bush repeatedly mentioning the Jordanian jailbird in his speeches. By the time we killed Zarqawi in June, he had become not only the face of the Iraqi insurgency but also the new poster boy of international terrorism.

Yet foreign fighters like Zarqawi remain a single-digit percentage of the Iraqi insurgency, and his dedicated group was considerably smaller still; a far greater danger is posed by the Shiite militias that have heavily infiltrated the same security forces that are supposed to stand up so that we can stand down. However, Zarqawi’s martyrdom has given President Bush and his surrogates an opportunity to recite with renewed conviction an old mantra that may yet save their party’s congressional majorities: We’re fighting them over there so we don’t have to fight them here. But even if we don’t reach an electoral tipping point (“stay the course” is likely to trump “cut and run”), a Republican escape this fall will be the 2004 buyer’s remorse all over again, with public approval for the president, Congress, and their war in Iraq quickly plunging to a new nadir. That’s because of Okinawa lesson number two: Every war, even a popular one, has a shelf life.

Our nation had been at war with Japan for three years and almost four months on the day we invaded Okinawa, almost exactly the same length of time we’ve been at war in Iraq. When major combat operations ended on Okinawa in late June 1945, more than 250,000 American servicemen, Japanese soldiers, and Okinawan civilians had died on the slender, 65-mile-long island. President Harry Truman (much admired by the current president) and his Secretary of War, Henry Stimson, both of them World War I combat veterans, looked at the dreadful casualties and extrapolated the figures for the invasion of the Japanese home islands, scheduled to begin in a few months. They concluded that the final conquest of Japan, essentially a giant Okinawa with 4 million soldiers dug into imposing defensive positions and a civilian population of 75 million prepared to pitch in with bamboo spears and carpenter’s awls, would probably cost upward of 1 million American lives and 20 million Japanese and require anywhere from eighteen months to ten years. Truman’s generals tried to fudge the numbers to sex up the invasion, but the buck-stops-here commander in chief knew enough about war to realize that the shelf life of his was running out. Which brings us to lesson number three: If you’re serious about winning your war, you need a Manhattan Project.

Truman gambled that in dropping two atomic bombs on Japanese cities, he could deliver a foreboding message to the intransigent Japanese militarists hunkered down in Tokyo and avoid an invasion that might well bring us to our knees. He had that option thanks to the foresight of his predecessor, who had authorized the bomb-building Manhattan Project, drawing together the best and brightest from all over the political spectrum to unravel nature’s fundamental secrets. Today we have an administration that prefers the expertise of the most loyal and ideological, and its idea of a Manhattan Project seems to be the “world’s largest embassy” we’re building in the middle of Baghdad’s hermetically sealed Green Zone. However, as many wise Iraq war supporters and opponents alike have noted, our hand in the global war on terror would be immeasurably strengthened if our Manhattan Project was an all-hands-on-deck initiative to develop alternative sources of energy and end our addiction to imported oil.

Truman’s gamble worked, and in another chapter of the Greatest Generation saga, my father came home, met my mother, and began to raise his family. Though he never wore a uniform again, I think he always loved the Navy, and he’d talk about life at sea and strange-sounding islands; we often laughed that he ran our house like a ship of the line. About war itself, less was said. He never once said he had risked his life so that I could be free, never passed a flag with a tear in his eye and talked about men he’d seen die for it. He could have received veteran’s disability benefits for the rest of his life, but he voluntarily discontinued them a few years after the war ended. Only late in his life did he set his Silver Star and Purple Heart atop a little keepsake box in a spare bedroom. The sole prerogative of his service that he expected was the right to say, when the conversation turned to subjects like Vietnam or Iraq, “Unless you’ve seen war, you don’t know.”

I don’t think I really had an idea what I didn’t know until I traced my dad’s life back to Okinawa. What he knew is the final lesson of his generation’s global war: War is not a virtuous activity. The men and women who wage it often possess great virtue, like my dad, but war itself never does. As a nation we recoil in horror at Abu Ghraib and Haditha. But on Okinawa, where the Japanese tortured and beheaded captive Americans, we routinely shot enemy prisoners; my father watched Japanese pilots machine-gunned as they parachuted into the sea. And it is no mere footnote that more than 150,000 civilians perished in Okinawa’s “typhoon of steel.” War is the best means to kill our fellow man; sometimes he richly deserves it and civilization must risk itself to give him his due. But war is not the best means for a nation to become more virtuous or spread its values, and we misunderstand its fundamental nature if we are shocked when it becomes truly ugly.

During this campaign season we will be reminded again and again that we are at war, but we should know that war has nothing to do with ribbons on the backs of SUVs and captive audiences of career soldiers hoo-rahing a president who will never have to adequately explain how he spent two years of his National Guard duty. But that’s just my opinion, because like all those steely-eyed podium patriots who so blithely took us to war in Iraq, everything I know about war I learned secondhand.