The following editorial appeared in Wednesday's Washington Post: On 'Fox News Sunday,' former Vice President Dick Cheney assailed the Obama administration for directing a prosecutor to conduct a preliminary inquiry into possible CIA abuses of terrorism suspects. Mr. Cheney asserted that President Obama had flip-flopped on an earlier promise to shield participants from liability. 'We had the president of the United States, President Obama, tell us a few months ago there wouldn't be any investigation like this, that there would not be any look back at CIA personnel who were carrying out the policies of the prior administration,' Mr. Cheney told host Chris Wallace. 'Now they get a little heat from the left wing of the Democratic Party, and they're reversing course on that.' That's not how it happened. In April, the administration released and repudiated a handful of Bush Justice Department memos blessing an array of interrogation techniques that bordered on or constituted torture. 'For those who carried out some of these operations within the four corners of legal opinions or guidance that had been provided from the White House, I do not think it's appropriate for them to be prosecuted,' Mr. Obama said at the time in a statement echoed by Attorney General Eric H. Holder Jr. The officials left open the possibility that those who engaged in behavior not sanctioned by the Justice Department could be legally vulnerable. The preliminary inquiry launched Aug. 24 makes real that possibility and focuses only on some 10 cases in which CIA operatives appear to have strayed beyond the limits of the Justice Department memos. Mr. Cheney is right when he argues that these incidents already have been investigated; prosecutors in the U.S. attorney's office for the Eastern District of Virginia and at Justice Department headquarters looked into the abuse allegations and concluded that prosecution was warranted in only one case, involving a CIA contractor. Under normal circumstances, that would and should be the end of the matter. Yet Mr. Cheney is wrong to argue that only partisan politics on the part of the Obama administration can explain the decision to reopen the cases. If anything, the politicization of the Justice Department during the Bush years is to blame for the need for further investigation to ensure that the decision not to prosecute was justified. Absent a truth commission to conduct a broader review of detainee policy -- which we continue to think would be the best approach -- Mr. Holder was right to call for a re-examination of these cases. Several detainees died in U.S. custody after undergoing interrogations; even though some of the deaths were ruled homicides, they have largely gone unpunished. We trust that special prosecutor John H. Durham, a respected Justice Department veteran, will review all of the facts, apply the law without fear or favor and bring good judgment to bear in making a decision. This is, unfortunately, more than we could say about the Justice Department during Mr. Cheney's watch. 