Joseph Persico, in the Montreal Gazette (April 19, 2004):

The U.S. president was receiving intelligence that an attack might occur imminently, probably not on the American mainland, but abroad.

Intercepted communications pointed to an adversary with a deadly history of surprise attacks. And, it did happen, the most horrific assault ever on U.S. territory, and one that would lead to war.

An investigation as to how so large a blow could have gone undetected was begun while the U.S. was still fighting the war.

One objective was to find out what the president knew about the threat, when did he know and what did he do to counter it?

The date in question, Dec. 7, 1941; the president, Franklin D. Roosevelt.

Today, a commission is investigating another surprise strike against the U.S. while the earlier disaster still foments speculation and controversy 63 years later. Did Roosevelt, as conspiratorialists maintain, know that Japan was about to attack Pearl Harbor, and did he fail to head off the assault to bring the U.S. into the Second World War?

How could FDR not have known? For more than a year, U.S. cryptanalysts had been breaking a key Japanese code.

In the six months before Dec. 7, 239 messages between Tokyo and the Japanese Embassy in Washington had been deciphered.

Given the information in his possession, if asked if Japan was going to attack, Roosevelt would doubtless have answered yes. Indeed, the latest decrypted data reaching him on the eve of Pearl Harbor had prompted Roosevelt to conclude: "This means war."

But if asked if he knew where an attack would occur, he would have had to say no. The intercepts had suggested strikes against the Philippines, Thailand, Malaya and the Russian maritime provinces. But not one of the 239 messages or any intelligence source available to FDR mentioned Pearl Harbor.

The charge that Roosevelt, by failing to repel the attack, found a back door into war raises this question: which war? It was not a secret that Roosevelt wanted to join Britain in the fight against Nazi Germany and that he had essentially launched an undeclared naval war in the Atlantic. The president had told the British prime minister, Winston Churchill, however, that a fight against Japan would be "the wrong war in the wrong ocean at the wrong time."

Churchill added: "We certainly do not want an additional war." What is often overlooked is that to get into the war that he did want, FDR had to depend on Hitler. It was Germany that, four days after Pearl Harbor, declared war on the United States. Roosevelt had no motive for war against Japan.

Still, conspiracy theories suggest, for example, that radio signals had been intercepted from the Japanese task force bearing down on Pearl Harbor. Commanders of this force, with no reason to protect Roosevelt's place in history, deny they ever broke radio silence. An historian as distinguished as John Toland has written that he interviewed the Navy radioman who picked up such signals, a claim the radioman has denied.

Pearl Harbor was an intelligence failure of stunning magnitude. The tragedy of Sept. 11, 2001, is equally so.

Whether in 1941 or 2001, the commander in chief must bear responsibility for intelligence debacles. To assign treasonous chicanery to FDR, however, is dead wrong.