Shocking though it was, the Christmas Day terror attempt by a 23-year-old Nigerian has only hardened Americans' awareness that they confront an implacable enemy in a war whose end is nowhere in sight. It is a hard-won new sense of reality and an invaluable one, achieved event by embittering event. The holy warrior assigned to blow up that passenger plane and who almost succeeded has, we learn, been granted the chance to strike a deal. His attack effort had come on the heels of the all-too-successful terror assault by that other Soldier of Islam, Maj. Nidal Hasan who murdered 13 fellow members of the American military. This, even as it was becoming clear that the number of our homegrown jihadis involved in terror plots, or who had enlisted in training toward that goal, had increased markedly.

It wasn't always easy to preserve a healthy sense of reality about terrorism in the years since 9/11, as the comments of ethical counselors, privacy advocates and civil liberties sentinels aghast at the possibility of government snooping have reminded us in the last week. They were around in force for media interviews, equipped as ever with a variety of arguments for the sanctity of privacy rights, warnings against surveillance that threatened the rights of citizens in a democracy. Day after day came the same breezy assurances—we had only to balance our security needs with privacy rights. As though, in this deadly war or any other, sane people could consider the values equivalent. The latest threat to privacy rights, advocates charged, was the use of full body scanners: the technology that would have immeasurably decreased the chances someone like Umar Abdulmutallab would have been able to get past security wearing his terror panties—intimate underwear, that is, in which 80 grams of PETN had been concealed.

It was that prospect of images revealing intimate areas of the body that apparently disturbed Rep. Jason Chaffetz, Utah Republican and sponsor of a House measure banning the use of full body scanners other than as a "secondary device"—i.e. to be used on select subjects. He didn't think, he told a New York Times reporter, "anybody needs to see my 8 year old naked in order to secure that airplane." A useful bit of reassurance, that, for the plotters of terror assaults who have in the past shown no compunction about the use of children as suicide bombers.

Another argument we heard frequently held that no matter what technology was put in place, our dauntless enemies would find ways to get around it. The picture was clear. With an unbeatable, ever resourceful enemy working night and day devising ingenious strategies, what point could there be in developing better detection capacities? Historians of the future may one day well ponder the powerful streak of defeatism in the U.S. in the era of its terrorist wars—and the superhuman characteristics Americans ascribed to their enemies in that 21st century battle against terrorism: a view in no small way nurtured in their media and political culture.

No guardians of privacy rights had weighed in earlier against the body imaging scanners than the American Civil Liberties Union. In October, 2007, the ACLU issued a statement decrying the use of this technology as "an assault on the essential dignity of passengers." "We are," the agency declared, "not convinced it is the right thing for America." This reasoning is clear. The right thing is for America to reject the scanners. Its citizens may then face increased risk of being blown up in mid-air but their privacy would remain inviolate to the end. Who could ask for anything more?

It took the president a second speech to weigh in on the issue of the security, or lack thereof, that had nearly led to tragedy. The first speech, two and a half days after the event, was in its own way noteworthy. In it the president observed that a passenger on the plane had "allegedly tried to ignite explosives. . . ." Mr. Obama's use of a familiar legalistic evasion would, it was soon clear, raise hackles—though the term is one routinely used in crime reporting. No matter. It was one "allegedly" too many in the world, jarring coming from the president in this circumstance.

Consider the justly famed speech an enraged American president delivered the day after Pearl Harbor. Then try imagining that address by Franklin Roosevelt—a leader to whom Mr. Obama has been compared—as it would sound in Obama language.

"Yesterday, December 7, 1941, a date that will live in infamy, the United States of America was suddenly and deliberately attacked by naval and air forces allegedly from the Empire of Japan . . . Yesterday the Japanese government allegedly launched an attack on Malaya. Last night Japanese forces allegedly attacked Hong Kong. Last night Japanese forces allegedly attacked Guam . . ."

Still it wasn't the president's comments but those of Janet Napolitano that reverberated. It wasn't the first time the Homeland Security chief's struggles to utter the kind of views she understood to be fitting for an Obama administration official ended in trouble—this time with interviews in which she made her now famous assertion that the airport security system had worked. She followed up, the next day, with retractions and clarifications that ended, as such things do, sounding worse than the original.

Asked in an interview with the German magazine "Der Spiegel" last March why she had avoided using the word "terrorism" in her testimony to Congress, she explained that she had instead preferred to use another term: "man-caused disasters." That choice of words demonstrated, she said, that "we want to move away from the politics of fear." The idea now, she added mysteriously, was to be prepared for all risks that could occur. There was nothing mysterious about the intended point. In the new forward looking administration she served—its leader had after all travelled far tendering apologies for his country's past sins and arrogance toward other nations—emphasis on terrorism was to be dispatched, along with the words war on terror and terrorists. The use of such references was to be equated with the low, the deceitful, the politics of fear, with indeed, a false claim of danger.

Ms. Napolitano would go on in other ways to prove the potency of man-made disasters—of which she was clearly proving one. In April, she issued a report seeming to target military veterans as potentially dangerous right-wing extremists. She soon apologized. In the same month she managed to suggest that the 9/11 terrorists had entered the U.S. through Canada, which appalled Canadian leaders. Apologies and clarifications followed.

Mr. Obama can't be happy with his Homeland Security chief. It's fair to say no president deserves an appointee so extravagantly unequipped for her job. Still there is much in Ms. Napolitano's attitudes and pronouncements, including talk of "the politics of fear," that reflect with glaring accuracy the Obama team's values, ideology and prime political targets. In her disastrous and raw way she is its voice revealed.

Terrorism will continue to provide its hardening education, though not entirely from terrorists themselves. We have before us now the spectacle of Jihadi Abdulmutallab, lawyered up, with full rights as though a U.S. criminal defendant. The impossibly expensive, dangerous, and unavoidably chaotic trial of Khalid Sheikh Mohammed and associates still lies ahead, slated for a Manhattan courtroom. Even now a majority of Americans can't fathom the reason for their government's insistence that the agents chiefly responsible for the 9/11 attack be tried under the U.S. criminal justice system with all due rights and constitutional privileges, instead of in a military court. That insistence itself is answer enough—an unforgettable testament to the ideological drives and related evasions of reality that shape this administration's view of the world.

Ms. Rabinowitz is a member of the Journal's editorial board.