We owe a debt of thanks to the Senate Homeland Security Committee for its report on the Ft. Hood jihadist massacre titled “A Ticking Time Bomb.” The Wall Street Journal column below provides a compelling insight into what the Senate committee found.

Over the past three years, we have put out numerous emails highly critical of political correctness, noting that PC can be annoying and even exasperating, but that when it comes to the threat of radical Islam, it can be deadly. Just as it was at Ft. Hood. Yet, every branch of the military issued a final report on the Fort Hood massacre. Not a single one mentioned radical Islam.

By Dorothy Rabinowitz

IN A MONTH OF MOMENTOUS CHANGE, it was easy to overlook the significance of another revolutionary event. Who would have believed that in the space of a few weeks the leaders of the three major European powers would publicly denounce multiculturalism and declare, in so many words, that it was a proven disaster and a threat to society?

One after another they announced their findings—Germany’s Chancellor Angela Merkel, Great Britain’s Prime Minister David Cameron, and France’s President Nicolas Sarkozy. Multicultural values had not only led to segregated communities: They had, Mr. Cameron noted, imposed policies of blind toleration that had helped nurture radical Islam’s terrorist cells.

There can be no underestimating the in-so-many-words aspect of these renunciations. This was multiculturalism they were talking about—official established religion of the universities, the faith whose requirements have shaped every aspect of cultural, economic and political life in Western democracies for the last 50 years. Still, they were out there—words coolly specific, their target clear.

They came at a fitting moment, just as Americans had been handed a report providing the fullest disclosures so far about the multiculturalist zeal that had driven Army and medical school superiors to smooth Nidal Malik Hasan’s rocky way through training, promote him, and, despite blatant evidence of his unfitness, raise not a single concern. Maj. Hasan, U.S. Army psychiatrist, would be assigned to Fort Hood where, in November 2009, he opened fire, killing 12 fellow soldiers and a civilian employee, and wounding 32 others.

In this report, titled “A Ticking Time Bomb” and put out by the Senate Committee on Homeland Security and Governmental Affairs, there is a detail as dazzling in its bleak way as all the glowing misrepresentations of Dr. Hasan’s skills and character, which his superiors poured into their evaluations of him. It concerns the Department of Defense’s official report on the Fort Hood killings—a study whose recital of fact made no mention of Hasan’s well-documented jihadist sympathies. Subsequent DoD memoranda portray the bloodbath—which began with Hasan shouting “Allahu Akbar!”—as a kind of undefined extremism, something on the order, perhaps, of work-place violence.

This avoidance of specifics was apparently contagious—or, more precisely, policy. In November 2010, each branch of the military issued a final report on the Fort Hood shooting. Not one mentioned the perpetrator’s ties to radical Islam. Even today, “A Ticking Time Bomb,” co-authored by Sen. Joe Lieberman (I., Conn.) and Susan Collins (R., Maine), reminds us that DoD still hasn’t specifically named the threat represented by the Fort Hood attack—a signal to the entire Defense bureaucracy that the subject is taboo.

For the superiors in charge of Hasan’s training at Walter Reed and his two years at Uniformed Services University of the Health Sciences, the taboo was of a more complicated order—one that required elaborately inventive analyses through which Hasan’s stated beliefs, ominous pronouncements, and evident unconcern with standards of behavior required of an officer could all be represented as singular virtues, proof of his exceptional value to the Army. It could not have been easy. Still, they managed.

They did so despite Hasan’s astounding trail of performances, each more telling than the next. To fulfill Walter Reed’s academic requirement for a presentation on a psychiatric theme, Hasan proffered a draft consisting almost entirely of wisdom from the Quran arguing for the painful punishment and liquidation of non-Muslims. Hasan evidently viewed the Qur’anic verses as a sufficient presentation—a view his superior didn’t share, given its lack of any mention of a psychiatric theme. When that guide warned him the presentation was “not scholarly” and might prevent his graduation, Hasan revised. The finished product was not much different. Still, Hasan was allowed to graduate.

He went on to his medical fellowship, where he soon delivered another class lecture, this one on the Islamist theme that the West, in particular the U.S. military, had mounted a war on Islam. The presentation brimmed with views sympathetic to Osama bin Laden, the motives of the 9/11 perpetrators, and suicide bombers. It so infuriated his classmates that their outraged eruptions caused the instructor to end the presentation.

There would be more of the same to come. One classmate witness told investigators that Hasan sought every possible opportunity to share his radical Islamist sympathies. His highest obligation, he told classmates, wasn’t to the Constitution, which he had sworn to protect and defend, but to his religion.

His Islamist sympathies would attract the interest of the FBI, which soon picked up on this U.S. Army major’s contacts with a terrorist suspect, unnamed in the Senate report. The agency would, however, have no continuing great interest in Hasan. Among other reasons, its agents had seen the impressive evaluation reports characterizing Hasan as an authority on Islam—one whose work even had “extraordinary potential to inform national policy and military strategy,” as one of his superiors put it in his officer evaluation report.

The same Hasan who set off silent alarms in his supervisors—the Psychiatric Residency Program Director at Walter Reed was one of them—would garner only plaudits in the official written evaluations at the time. He was commended in these as a “star officer,” one focused on “illuminating the role of culture and Islamic faith within the Global War on Terrorism.” One supervisor testified, “His unique interests have captured the interest and attention of peers and mentors alike.” No single word of criticism or doubt about Hasan ever made its way into any of his evaluations.

Some of those enthusiastic testaments strongly suggested that the writers were themselves at least partly persuaded of their reasoning. In magical thinking, safety and good come to those who obey taboos, and in the multiculturalist world, there is no taboo more powerful than the one that forbids acknowledgment of realities not in keeping with the progressive vision. In the world of the politically correct—which can apparently include places where psychiatrists are taugh—magical thinking reigns.

A resident who didn’t represent the diversity value that Hasan did as a Muslim would have faced serious consequences had he behaved half as disturbingly. Here was a world in which Hasan was untouchable, in which all that was grim and disturbing in him was transformed. He was a consistently mediocre performer, ranking in the lowest 25% of his class, but to his evaluators, he was an officer of unique talents.

He was a star not simply because he was a Muslim, but because he was a special kind—the sort who posed, in his flaunting of jihadist sympathies, the most extreme test of liberal toleration. Exactly the kind the progressive heart finds irresistible.

A decision as to whether Maj. Hasan will go to trial—it would be before a military court-martial—should be forthcoming next month. He stands charged with 13 counts of premeditated murder, committed when he turned his laser-equipped semi-automatic on members of the military at the Soldier Readiness Center. The likelihood is that the trial will go forward. If it does, the forces of multiculturalist piety, which played so central a role in advancing this Army major and concealing the menace he posed, will be the invisible presence on trial with him.

Ms. Rabinowitz, a member of the Journal’s editorial board, is the author of “No Crueler Tyrannies: Accusations, False Witness And Other Terrors Our Times” (Free Press, 2003).