Pearl Harbor on a Sunday morning was the most peaceful place in the American armed forces.
Sunday was the day nothing happened. Half the crews were ashore. Bands were assembling on the sterns of the battleships to play the national anthem at eight o'clock, as they did every morning, and men were queueing for breakfast, and some were still asleep.
The battleships were moored along the eastern side of Ford Island in the middle of the harbour, in pairs, in a neat row that everybody called Battleship Row.
At seven fifty-five in the morning the first bombs fell, and a signal went out from the naval headquarters that has been quoted ever since, because of the flat way it puts it. Air raid Pearl Harbor. This is no drill.
Japan's problem in nineteen forty one was oil, and it was a problem Japan had largely created for itself.
Japan had been at war in China since nineteen thirty seven, and in the summer of nineteen forty one moved into southern Indochina. The United States responded by freezing Japanese assets and cutting off oil exports, and Japan imported around eighty per cent of its oil from the United States.
That left Japan with a stark choice: withdraw from China, which its government regarded as unthinkable, or seize the oilfields of the Dutch East Indies, which meant war with the United States and Britain.
The plan Admiral Yamamoto produced was not a plan to win a long war. He said so explicitly, and he had lived in America and studied there and had a clearer idea than most of what American industry could do. He is supposed to have said that he could run wild for six months, and that after that he had no expectation of success.
The idea was to destroy the American Pacific Fleet in one blow, seize everything needed within those six months, and hope that America would decide the cost of taking it back was too high.
There were warnings. There are always warnings, and this is the part of the story worth studying, because none of them worked.
At about a quarter past seven, two privates at a radar station on the northern tip of the island were finishing a training shift and kept the set running for practice. They saw something enormous on the screen, more than a hundred aircraft, about a hundred and thirty miles out.
They telephoned the information centre. The officer on duty there was new, and he knew that a flight of American bombers was expected in from California that morning, from roughly that direction. He told them, in a phrase that has followed him for the rest of history, not to worry about it.
An hour before that, a destroyer had spotted and sunk a small submarine trying to slip into the harbour entrance. The report went up the chain and was still being confirmed when the aircraft arrived.
And in Washington, decoded Japanese diplomatic traffic had made it clear that something was about to happen somewhere. A warning was sent to Hawaii that morning. It was sent by commercial telegram because of atmospheric interference on the military circuits, and it was delivered by a messenger on a bicycle, several hours after the attack was over.
The attack came in two waves and lasted about two hours in total.
The battleship Arizona was hit by a bomb that reached a forward magazine, and she blew up. More than a thousand men died in that single explosion, which is nearly half of all the deaths of the day. She sank where she was moored and she is still there.
The Oklahoma was hit by torpedoes on her port side and rolled completely over, trapping men inside the hull. Rescuers cut into the upturned bottom for the next two days and got thirty-two men out. Others were still tapping when the tapping stopped.
In total, eight American battleships were sunk or damaged, along with a number of smaller ships. About a hundred and eighty aircraft were destroyed, most of them on the ground, parked in tidy rows in the middle of the airfields, where they had been put to make them easy to guard against sabotage.
Two thousand four hundred and three Americans were killed. Sixty-eight of them were civilians.
Japan lost twenty-nine aircraft.
By the measure the attack was designed for, it was a brilliant success. By the measure that turned out to matter, it failed on three separate counts.
The first is the one everybody knows. The American aircraft carriers were not in the harbour. All three assigned to the Pacific were at sea or on the mainland. Within six months it would be entirely clear that carriers, not battleships, decided battles at sea, and Japan had sunk the wrong category of ship.
The second is less famous and arguably as important. The Japanese commander decided against launching a third wave. The targets of a third wave would have been the fuel storage tanks, the dry docks and the repair shops.
Pearl Harbor held around four and a half million barrels of oil in tanks above ground, undefended. Losing that would have pushed the American fleet back to California for a year or more. The dry docks meant that damaged ships could be repaired where they were, and most of the battleships sunk that day were raised, repaired and returned to service.
The third failure was not military at all. Japan had intended to deliver a declaration before the attack. Difficulties with decoding and typing at the Japanese embassy in Washington meant it was handed over more than an hour after the bombs fell.
So a country that had been bitterly divided about entering the war stopped being divided by lunchtime.
The following day, President Roosevelt spoke to Congress for a little over six minutes.
He called the seventh of December a date which will live in infamy, and he had written that word himself, over a typed draft that originally said a date which will live in world history, which is a much duller sentence.
Congress declared war with one vote against. It came from Jeannette Rankin of Montana, who had also voted against entering the previous war, and who said that as a woman she could not go to war and refused to send anyone else.
Three days later, Germany declared war on the United States, which it was under no treaty obligation to do, and which remains one of the more baffling decisions of the period. That declaration is what turned an American war in the Pacific into an American war in Europe as well.
Yamamoto's six months were up in early June nineteen forty two, at an island called Midway, which is the subject of a later episode in this series.
The two privates at the radar station were Joseph Lockard and George Elliott. Neither was disciplined and both were later commended, which is right, because they did everything correctly. The failure was not theirs.
There is a persistent story that Roosevelt knew in advance and let it happen. Historians have gone through this repeatedly for eighty years and there is no evidence for it. What the evidence shows is far more ordinary and far more useful: a great deal of information, spread across several organisations that did not share well, with no one person holding all the pieces.
The Arizona still leaks a small amount of oil, a few drops a day rising to the surface. Visitors call it the black tears. There is a memorial built across her, and eleven hundred and two men are still aboard.
Here is something to think about tonight. Every warning that day was received by somebody who had a perfectly sensible explanation ready for it. Nobody was lazy and nobody was stupid. How would you build a system that catches the one strange thing among a hundred ordinary ones?