LAST WEEK we questioned whether there was a difference between President Bush and Sen. John F. Kerry on the crucial question of U.S. policy for handling prisoners captured abroad. Mr. Bush continues to take the position that the Geneva Conventions should not be applied to many detainees, including anyone captured in Afghanistan, and that harsh interrogation techniques foresworn by the U.S. military for decades should be used on some of these prisoners. Mr. Kerry critiqued the shocking abuses that have resulted from that decision, at Abu Ghraib prison and elsewhere, but not the policy itself. Now Mr. Kerry has taken a stand. In a statement drawn up in response to our questions, the Democratic nominee declares that "a Kerry administration will apply the Geneva Conventions to all battlefield combatants captured in the war on terror."

The result is an important new distinction between the presidential candidates. In our view, Mr. Bush's decision in February 2002 to set aside the Geneva Conventions was one of the most damaging mistakes of his presidency. It led directly to the imprisonment of hundreds of foreigners at Guantanamo Bay without any legal process, until the Supreme Court intervened earlier this year. Mr. Bush's decision also led to the sanction by senior administration officials, including Defense Secretary Donald H. Rumsfeld, of harsh interrogation techniques that are illegal under the Geneva Conventions. As several official investigations have found, these techniques soon "migrated" from Guantanamo to U.S. field units in Iraq and Afghanistan, leading to hundreds of cases of torture, homicide and other abuse, and a shameful stain on the international reputation of the United States.

Mr. Bush and Mr. Rumsfeld still refuse to acknowledge the terrible consequences of the decisions they made, much less correct their mistakes. In a letter published on this page today, Mr. Rumsfeld's spokesman, Lawrence Di Rita, once again claims that no policy or decision made by a senior official had anything to do with the abuses at Abu Ghraib. To bolster his case, he selectively cites official investigations that have, in fact, proven the opposite. For example, Gen. Paul J. Kern, whom Mr. Di Rita quotes, testified to Congress last month that techniques approved by Mr. Rumsfeld in December 2002 -- including nudity, painful stress positions and the use of dogs to incite fear -- "found their way into documentation that we found in Abu Ghraib." The Schlesinger commission, also cited by Mr. Di Rita, determined that Iraq commander Lt. Gen. Ricardo S. Sanchez approved similar practices, "using reasoning from the President's memorandum" of 2002. It also concluded, "There is both institutional and personal responsibility at higher levels" for the crimes at Abu Ghraib.

Without any change in policy, there is every reason to expect that a second Bush term would produce more scandals like Abu Ghraib. As the history of the past three years demonstrates, such abuses result when the rule of law is set aside. That's why we welcome Mr. Kerry's pledge to resume full U.S. compliance with the Geneva Conventions. Such compliance does not prevent a U.S. president from holding enemy combatants indefinitely or from denying them prisoner-of-war status. It does not prevent American forces from conducting interrogations. But it does ensure that the United States will operate according to the same international standards that it wishes to see applied to its own service members and citizens. "We will abide by a principle long enshrined in our military manuals," says the Kerry statement: "That America does not treat prisoners in ways we would consider immoral and illegal if perpetrated by the enemy on Americans." That strikes us as a policy that is both more in keeping with American standards, and more likely to be successful in practice, than that pursued with such disastrous results by Mr. Bush.