Zero-tolerance on torture: How hard is that?

It is good that Congress and the military are seriously investigating past abuses at Abu Ghraib and other US-run detention centers around the world.

However, simply investigating past abuses isn't enough. Beyond that, President Bush and Congress need to declare - and then verifiably implement - a policy of zero tolerance for torture.

There are a number of reasons such clear, high-level leadership is needed on this issue:

• Any signal that torture or physical or mental abuse of detainees might be condoned in high places is a slippery slope that invites policy implementers at all levels to try to "push the envelope" just a bit further.

In this respect, the original announcement by administration leaders that detainees in Guantánamo would not have the protections offered by the Geneva Conventions opened the way to abusive practices there that were later exported to prisons in Iraq, including Abu Ghraib. Similar practices also have been reported in Afghanistan.

Israel is another place where the slippery slope has evidently operated. There, the courts explicitly allowed the use of "moderate physical pressure" in cases where extracting details about a "ticking bomb" could arguably save lives. But now, Israel's security services apply physical and mental pressure to thousands of detainees almost routinely, and no longer even claim that a bomb was ticking in all those cases.

A clear announcement by President Bush that no form of torture or physical abuse by US employees or contractors will be tolerated is the only way, today, for the US government to step decisively off this dangerous slope.

• Announcing and verifiably enforcing a clear zero-tolerance policy is easily the smartest response Washington can make to the revelations about past abuses.

The campaign against global terrorism can be won only by assembling and sustaining a broad international alliance.

If Washington continues to allow some forms of physical or mental pressure, or to deny the applicability of the Geneva Conventions to some detainees, that will seriously curtail the effectiveness of this campaign.

Intelligence specialists generally give little credence to "information" exacted under duress. Meanwhile, upholding the validity of the Geneva Conventions gives the best chance of ensuring that US service members receive acceptable treatment if they fall into hostile hands.

• The US is contractually obliged to prohibit and prevent all torture and abuse of detainees. In 1955, the Senate ratified the Geneva Conventions, which prohibit inflicting torture - or cruel, humiliating, or degrading treatment - on detainees. In 1994, it ratified the International Convention against Torture, which commits the US to preventing acts of torture "in any territory under its jurisdiction." This convention describes torture as any act undertaken by a government official or contractor, "by which severe pain or suffering, whether physical or mental, is intentionally inflicted on a person for such purposes as obtaining ... information or a confession, punishing him ... or intimidating or coercing him."

• Most Americans would probably support their president's adoption of a clear antitorture stand. A recent Washington Post/ABC News poll found that 64 percent of Americans said that torture is "never acceptable," even against people suspected of involvement in attacks against US forces in Iraq or Afghanistan, and 52 percent described "physical abuse that falls short of torture" as unacceptable in those cases.

If the president announces a zero-tolerance policy, and gives clear arguments why it makes sense, he could probably win even broader public support.

• Pursuing a clear policy of zero tolerance for torture is, quite simply, the right thing to do. US personnel and contractors have inflicted great harm on foreign detainees in the past 30 months.

Those wounds need to be healed and, yes, rigorous investigations into how those abuses came about still need to be pursued.

But all actions to mitigate the harms of the past will count for little if agents and contractors of the US government continue to practice torture or abuse going forward from now.

• Helena Cobban is working on a book about violence and its legacies.