From C.J. Chivers, the New York Times: In a report quietly made public early this month, a United Nations commission pointedly noted that after examining the destruction in Majer , interviewing survivors, reviewing documents and conducting an analysis of satellite imagery from before and after the attack, it found no evidence that “the site had a military purpose.”

It added that “it seems clear that those killed were all civilians.”

The commission recommended that NATO investigate this bloody occurrence (and several others that have been ferreted out in the face of repeated official denials) and follow its own practices in Afghanistan for taking responsibility for civilian casualties and making compensation payments.

Then a well-established pattern repeated itself. NATO’s secretary general, Anders Fogh Rasmussen, said the alliance had examined the allegations of civilian casualties and, essentially, had nothing to account for. “This review process has confirmed that the targets we struck were legitimate military targets,” he said.

NATO presented no evidence supporting this claim. Instead, it has declined repeated requests — including from survivors — to release weapons-systems video or other material demonstrating that anyone but civilians was present where and when the bombs struck.

In previous statements, Mr. Rasmussen had said that there were no “confirmed” civilian casualties caused by NATO in the entire war. That ringing denial overlooked two points: NATO’s definition of a “confirmed casualty” is a casualty that has been investigated by NATO; and because the alliance has refused to look into credible allegations of the scores of civilian deaths that independent investigations have found it caused, it is impossible for the official tally to rise above zero.

The questions surrounding NATO’s attacks in Majer — the worst known case of the alliance’s causing civilian casualties in its campaign to protect civilians — are not just at the center of the struggle for a more complete sense of a complicated air campaign. . . .

In this context, it is important to remember that the United Nations did not cast the killings in Majer as war crimes, as it did many of the killings in Libya by pro- and anti-Qaddafi forces. Rather, impartial investigators largely agree that NATO painstakingly tried, within the limits of a war where almost all of the airstrikes were made without the help of tactical air controllers on the ground, to minimize risks to civilians.

The violence that killed civilians seems to have stemmed from assumptions, not intent. NATO statements make it clear it believed that the buildings leveled that night housed a loyalist command node. What led to such assumptions? What might have prevented these assumptions or tested them more fully before the ordnance was released? These are grounds for thoughtful reflection and study.

C.J. Chivers is a reporter in Iraq, Afghanistan and Libya for The New York Times(graphic: NATO)