Every generation has an event that galvanizes and defines them, an event for which they look back and remember where they were at that exact moment, and knew their lives would change forever. For my parents' generation, it was the attack on Pearl Harbor.

For those who missed it, we recently passed the 65^th anniversary of the Date that Will Live In Infamy, the attack on the US Pacific Fleet at Pearl Harbor by the Imperial Forces of Japan on December 7, 1941. This anniversary marked, in all likelihood, the last great gathering of Pearl Harbor veterans, many of whom are in their mid-80s and many of whose comrades have died off. Older, grayer, and more infirmed than the young men they were on that Sunday morning, they still have an ineffable spirit, particularly those who, like one veteran, said he would keep coming back to Pearl Harbor as long as he had life in his limbs.

The battles fought after Pearl Harbor propelled the United States into the Second World War were punctuated by cries of "Remember Pearl Harbor" and, more specifically, "Remember the Arizona." The Arizona and the remains of its crew still lie entombed at the bottom of Pearl Harbor. The names of the men who died on the Arizona are listed on the Arizona memorial, a graceful structure that spans the sunken vessel. More poignant is the columbarium: survivors of the Arizona who lived out a full span of years nonetheless have come back to the Arizona, their cremated remains resting forever with their entombed shipmates. If there is anyone who can visit the Arizona without being moved to tears, he has a heart of stone.

There is a book by historian Victor Davis Hanson that I rather like, called Ripples of Battle, about how the battles of the past echo through history, influencing how we fight, what we think and how we live. Pearl Harbor has continued to ripple through my parents' lives -- and mine -- on both a personal and professional level.

The first US admiral to be killed in WWII was Admiral Ike Kidd, who still lies entombed in the Arizona. His widow lived a couple blocks from my parents when I was growing up in Annapolis, his son (also an Admiral) my parents met many times, and his grandson was a year or two ahead of me at the prep school I attended (and later attended the Naval Academy -- the third generation of Kidds to serve in the Navy). Another beloved neighbor (with whom I attended my first Army-Navy game) had been the berthing officer at Pearl Harbor, the guy who decided where the ships were parked that fateful day.

I could hardly turn around growing up without remembering Pearl Harbor. My father was stationed at Hickam Field, Honolulu in the 1950s, and there were still bullet holes from the attack scarring the buildings. My sister was stationed at Pearl Harbor decades later and there were still bullet holes in the buildings, left there "to remember." A colleague at Oracle stationed in Hawai'i a few years ago assures me that bullet holes still remain in many buildings at Schofield Barracks. Nobody in the military can ever forget Pearl Harbor. We would all do well to remember it.

The ripples of Pearl Harbor spread wide. America, keen to exact a measure of retribution, launched a retaliatory raid on Tokyo. (A damnfool idea if ever there was one, flying B25 Mitchell bombers off the aircraft carrier Hornet, except that it worked.) The Doolittle Raiders successfully bombed Tokyo April 18, 1942, a feat which Japanese military leaders had told Emperor Hirohito was impossible. Though there was little physical damage, there was considerable damage to the Japanese military psyche. As a result, Japan was determined to destroy the remains of the US fleet, and sailed for Midway six weeks later. Because of Pearl Harbor, the Doolittle Raiders attacked Tokyo, because of the Doolittle Raid, Japan came to Midway, where they lost the war.

Admiral Yamamoto, who meticulously planned the attack on Pearl Harbor, nonetheless felt that it was a strategic mistake. "I fear all we have done is to awaken a sleeping giant and fill him with a terrible resolve," he said. He did not live to see the defeat of Japan; his plane was shot down over Bougainville in 1943. In an eerie coincidence, his plane was shot down a year to the day of the Doolittle Raid.

In the 1920s, a Marine Corps officer named Col. Earl Ellis foresaw the rise of militarism in Japan, and the Marine Corps listened to him. The Marines developed their amazing amphibious warfare capabilities in part because of the vision of Col. Ellis, who foresaw that a war with Japan would necessarily involve storming beaches and taking back islands. The rest, as they say, is history. My mother once was in the uncomfortable position of being asked, by the Japanese ambassador to the US (who was attending a Navy football game at Navy-Marine Corps Memorial Stadium in Annapolis at the time), what the names were emblazoned across the stadium? (They were, in fact, the names of great Navy and Marine Corps battles, a number of which were from WWII: Guadalcanal, Tarawa, Peleliu, Iwo Jima, Okinawa.) That there was no diplomatic incident I ascribe to my mother's great tact. We think Pearl Harbor was an attack out of the blue, but it wasn't, not really. That the US ultimately prevailed in the Pacific was due in some measure, to people like Col. Ellis reading the handwriting on the wall and planning for a future years ahead.

A drawback of the information age is that so many people's memory spans only the latest round of technological innovations, but the ripples of history play out in years, not nanoseconds. History is timeless; technology, as we know, is all too temporal. The lessons of history, too, are timeless, if we care to learn them.

The biggest and most formidable lesson of Pearl Harbor is the unobvious one. A number of studies before Pearl Harbor described the possibility of a Japanese attack. However, few believed that Japan would actually do such a thing. The key takeaway from Pearl Harbor is one of the lessons that seem to be learned, and forgotten, and relearned again through history, a ripple that never ends: where there is capability, an enemy may develop intent. Woe to those who only consider what they think will happen instead of what may happen. A good history lesson, a good security lesson, a good life lesson. Where there is capability, an enemy may develop intent.

As Col. Ellis did, we need to think the unthinkable. Where there is capability, an enemy may develop intent. It is only after we think the unthinkable in the technology world that the industry as a whole will be able to adequately protect against looming threats.

On a family trip as a child, we happened, strictly by chance, across the USS Missouri, which was then in mothballs in Bremerton, Washington. I had no idea why a wistfulness crossed my father's face, until he explained to me that he participated in the flyover of the USS Missouri in Tokyo Bay when the peace treaty ending the war with Japan was signed. It seems fitting to me that the USS Missouri resides today in Pearl Harbor: the site of the end of the war docked a short distance from the Arizona, where it all began. Rest in peace, faithful warriors.

Remember Pearl Harbor.