Of course I already knew the basics. On a quiet Sunday morning, December 7, 1941, the Imperial Army of Japan attacked the United States of America. President Franklin D. Roosevelt declared war on Japan, and the US entered World War II.I wasn’t familiar with the details, and have been mulling over the lessons of a recent visit to Pearl Harbor in the somber nine days before Tisha Be’av.I was invited to Honolulu to speak about Israel. There was a variety of audiences, including public radio. Yes, there are Jews in Hawaii – an estimated 10,000. The 50th state’s former governor Linda Lingle was Jewish, as is the current deputy governor, Brian Schatz. And yes, the Jews of Hawaii are concerned about Israel. I’m always moved by how attached our brethren in far-flung Jewish communities are to Israel, and you don’t get much farther flung than Hawaii. Indeed, one of the synagogues in Honolulu is called Sof Maarav, from the famous Yehuda Halevy poem, “My heart is in the east, but I am in sof ma’arav” – the uttermost west – 12 time zones from Jerusalem, and because there’s no daylight saving time, 13 hours’ time difference.The Hawaiian reputation for hospitality is well-deserved: From the moment I arrive I am draped in flowers. Each lei is fashioned from 80 orchids. My hosts take me to watch the sunset at Waikiki Beach, to see President Barack Obama’s birth hospital and apartment block, and to the Pearl Harbor National Historical Site.Over a million and a half adults and schoolchildren visit Pearl Harbor and the WWII Valor in the Pacific National Monument every year, including many Japanese tourists. Displays of authentic WWII aircraft, ships and a submarine are interspersed with audiovisual material illustrating the period. The highlight of the visit is a short sail to the Memorial to the Fallen, near the USS Arizona, which still lies sunken in the harbor.On the day of infamy, as FDR called it, 353 Japanese aircraft succeeded in reaching Pearl Harbor. They dropped specially fitted bombs that could pierce the decks of supposedly impenetrable battleships, and launched torpedoes from the air. Two thousand four hundred soldiers and civilians were killed, and Battleship Row of the American fleet was decimated; 1,177 servicemen were killed on the Arizona, to which 37 sets of brothers had been assigned. Most of the bodies are still on the ship, joined by those of survivors who until today choose the Arizona as their final resting place.The operative question throughout the somber visit is, of course, how the US could have been caught unprepared.The US fleet had been positioned in Hawaii to demonstrate American muscle as a deterrent to Japanese expansionism. But the museum narrative suggests that from the Japanese point of view, the oil embargo America had placed on Japan was the equivalent of a declaration of war. An astute intelligence report submitted to both the US Army and Navy prior to December 7 anticipated a drastic action on the part of the Japanese. It even outlined the possibility of an airborne attack, detailing the probable choice of a Sunday or holiday and the approach from the north. It wasn’t taken seriously. The US relied instead on a newly installed aerial warning system – radar – and didn’t conduct rigorous sky patrols.For the past seven decades, the mistakes made at Pearl Harbor have been endlessly reviewed. Japan’s Zero bombers were poorly thought of. The 160,000 Japanese Hawaiians were considered a greater threat than the Japanese in Japan. When the first wave of Japanese planes approached, the radar did indeed pick them up, but no attention was paid because a delivery of American planes was expected. A Japanese submarine caught entering Pearl Harbor wasn’t recognized as part of an integrated attack.Military decision-makers simply couldn’t understand the thinking of the Japanese, nor appreciate their ingenuity. Overconfidence colored the decision-making process. And as we all know, once you’ve made up your mind, new evidence that contradicts your beliefs is so uncomfortable that we usually reject it. The term is cognitive dissonance.Today, visitors to Pearl Harbor must surrender purses and bags at the gate – a puzzling security regulation that dates from the second surprise attack on the US, on September 11, 2001. My hosts pay $3 to store my purse while I am allowed to carry my camera and phone.The attack on the Twin Towers, the 10th anniversary of which we are marking soon, is another example of poor comprehension of the ideology, intent and ingenuity of an enemy. Here, too, intelligence went against conventional thinking, and nearly 3,000 men and women were murdered.How well we in Israel know the dangers of overconfidence, and the failure to gauge the enemy’s determination. The inability to foresee the Yom Kippur War is the most blatant example, but there have been many others, like boasting that Saddam Hussein’s missiles were so inexact they would never hit Tel Aviv, or sending commandos onto the Mavi Marmara armed with paint guns. To say nothing of our failure in public relations.On the way back from Pearl Harbor, my hosts drive me near a hillside tea house from which a spy on the top floor, using simple binoculars, was able to see the entire military base. While locals were drinking tea, daily reports on how the planes were parked and the carriers were docked were dispatched to the enemy.The Japanese also miscalculated. They didn’t realize that the attack would unify the American people in their readiness to go to war.These days of Av, in which we remember the destruction of our two Temples in Jerusalem and the calamities of modern history, should be an antidote to cocksureness. Our enemies always have their binoculars turned toward us. Our domestic concerns, legitimate though they are, cannot distract us from keeping watch at this unstable time in the Middle East.The author is a Jerusalem writer who focuses on the stories of modern Israel. She serves as the Israel director of public relations for Hadassah, the Women’s Zionist Organization of America. The views in her columns are her own.