A little history can help sort out the current dispute over how far to go and how soon to go in investigating the intelligence failure that allowed radical Islamic hijackers to crash passenger jets into the World Trade Center and the Pentagon. The nation went through it once before, in the aftermath of the Japanese sneak attack on Pearl Harbor in 1941. Today’s calls by Democrats and some Republicans for a full investigation seem tepid, and the Bush administration’s outraged resistance and complaints of hindsight and second-guessing seem defensive when contrasted with what happened in the 1941 crisis.

On the night of the Dec. 7 Pearl Harbor attack, when much of the U.S. Pacific naval fleet and war planes on the ground had been destroyed, President Franklin D. Roosevelt summoned congressional leaders to the White House to meet with the Cabinet. He told them he was going to call for a declaration of war at a joint session the next day. Sen. Tom Connally of Texas said what was in all of their minds. “How did it happen that our warships were caught like tame ducks in Pearl Harbor?” he shouted, banging on his desk, his face purple, as recounted by the historian Doris Kearns Goodwin. “Where were our patrols? They knew these negotiations [with the Japanese, trying to head off a war] were going on. They were all asleep.”

Ten days later, on Dec. 17, Mr. Roosevelt appointed a presidential commission to examine the facts and fix responsibility for the disaster. He named Supreme Court Justice Owen J. Roberts to head the commission. It presented its report a few weeks later. Many other investigations followed and some facts still are disputed, but the point is that a wartime leader acted promptly to fix the system. Wartime unity did not suffer. In fact, it benefited.

This time, too, there is plenty of reason for investigation and disclosure of what went wrong and why. We need an appraisal of what was done about a presidential briefing memo of Aug. 6 that The Washington Post reports carried the title, “Bin Laden Determined to Strike in U.S.” We need to know why the White House was not told about a 1999 report that terrorists associated with Mr. bin Laden might hijack an airplane and crash it into the Pentagon, the White House or CIA headquarters. The report was prepared for the National Intelligence Council, an affiliate of the CIA.

These are only two of the obvious questions becoming known about the intelligence failure. A strong national leader should welcome inquiry, not to fix blame but to fix the intelligence system for better preparation for future terrorist attacks likely to come. A presidential commission, perhaps headed by a respected Supreme Court justice like Justice Roberts, would be a good immediate response.