How should countries deal with a legacy of brutality authorised by a previous government? The question has loomed large since the 1980s, as one after another country in Latin America and elsewhere shed military regimes that had shattered the sacred bond of humanity through state-sanctioned torture, disappearances and other depredations. Their societies faced agonising dilemmas. How should they deal with the torturers in their midst, who often remained a potent political force? And how could newly elected leaders best ensure their countries would never again descend into the abyss of lawless violence approved by immediate predecessors?

Today, scores of countries have faced their own version of these questions – just last week, a truth commission in Brazil published a report detailing torture methods used from 1964 to 1985. It is fair to say that confronting the past has been easy for none of them. Often, as I saw other countries confront these questions in the 1980s and 90s, it was hard to imagine they would become relevant to my own country at the dawn of a new century. Much less did I imagine that Americans would find it so hard to acknowledge the full extent of torture committed by agents of our government and, harder still, to condemn their acts without equivocation.

The long-delayed and hard-fought release last week of a Senate intelligence committee report, which recounts in unsparing detail the CIA’s post-9/11 programme to detain and interrogate those suspected (often incorrectly) of terrorism, was a milestone in our painful process of reckoning. But it was also a reminder of how far we still must go.

Last week, few political leaders seemed to grasp the moral imperative of such a reckoning as keenly as Senator Dianne Feinstein, who chairs the intelligence committee and fought relentlessly to release the 528-page document. As other senators thundered against the report and warned of the dire consequences its release would provoke, Feinstein rose to the floor to condemn the “brutality” detailed in it that stood “in stark contrast to our values as a nation”. As Senator Feinstein recognised in her foreword, the report is, above all, a call to learn “the lessons of our history”.

This was not the first congressional effort to investigate the United States’ descent into what former vice-president Dick Cheney called “the dark side”. In November 2008, the Senate armed services committee released a report documenting the army’s role in torture at Abu Ghraib and elsewhere. On his second day in office, moreover, President Obama adopted an executive order banning torture. There should have been no doubt that US law already banned torture. But the new president recognised how deeply the previous administration’s justifications for torture, accompanied by deformed interpretations of law, had penetrated public discourse and institutional culture.

Even so, in the already deeply polarised atmosphere in which he took office, Obama drew the line: There would be no broad-ranging effort to confront the past. Days before he took office in January 2009, the president-elect signalled his reservations about proposals to establish a South Africa-style truth commission, saying he believed “that we need to look forward as opposed to looking backwards”.

In the years since, President Obama has walked the same fine line he drew in 2009. On the one hand, he has consistently made clear that torture is unacceptable under any circumstances. But the administration has made scant use of its authority to investigate those responsible, limiting prosecutions to low-level perpetrators in isolated cases.

Despite his continued opposition to a wide-ranging truth commission, Obama has acknowledged the need to confront, condemn and learn from our past. After the Senate intelligence committee released its report, he welcomed its release, stating: “One of the strengths that makes America exceptional is our willingness to openly confront our past, face our imperfections, make changes and do better.”

But the moral message of Obama’s statement was muddled by the more robust defence he allowed CIA director John Brennan to mount. Two days after the report was released, Brennan called the process that led to the report as “flawed,” and characterised the “transparency that has happened over the last couple of days” as “over the top”. While acknowledging that some “abhorrent” methods used by the CIA were “outside of the bounds” of approved policy, Brennan questioned a central conclusion of the report – that the torture was not only abhorrent, but clearly ineffective.

The Senate inquiry was not the equivalent of a comprehensive truth commission launched by executive action. Still, I could not help comparing the administration’s cautious embrace of its report with the symbolically resonant actions of leaders in other countries that established truth commissions. A crucial moment in the work of such commissions has been the presentment of their final report to their country’s leader – and his or her acceptance of the full burden of history recounted in the reports.

Why does it matter how consistently or robustly the administration embraces the findings of the Senate report as long as the president himself has renounced torture? Is it time, as Obama administration counter-terrorism adviser Lisa Monaco suggested the day the report was released, to “put a period at the end of this chapter and… move on”?

I believe it is naive to think we have completed the hard work of restoring what we lost when our country breached core values of humanity after 9/11. The Senate report did a great service in demonstrating how far we allowed our public servants to stray from the basic code of decency that has for so long formed part of our national creed.

In the wake of its release, many prominent opinion leaders have condemned the practices it laid bare. But the report has not yet put to rest public debate about torture. Never mind Dick Cheney’s description of the report as “full of crap”, American media still hesitate even to call the practices described in the report as “torture”. Instead, it remains common practice to qualify use of the word by attributing it to a particular source, as the Washington Post did when it wrote that the report’s “central conclusion is that harsh interrogation measures, deemed torture by programme critics including President Obama, did not work”.

Their reticence reflects a lingering ambivalence about Bush administration tactics. This past week, I found myself in conversations with enlightened friends and relatives who asked whether, given the threats our country faced after 9/11, torture wasn’t justified. Many leading America rights advocates still hesitate to press their government to prosecute those responsible – a standard call when other countries sanction torture and an obligation of my country as a party to the convention against torture. In short, it will take time, hard work and courage to face what we did, and ensure we won’t again be tempted to use abhorrent practices when we are tested afresh.

Diane Orentlicher is professor of international law at American University, Washington DC