WASHINGTON — A bipartisan Senate report released Thursday concludes that decisions made by former Defense Secretary Donald H. Rumsfeld were a "direct cause" of widespread detainee abuses, and that other Bush administration officials were to blame for creating a legal and moral climate that contributed to inhumane treatment.
The report, endorsed by Democrats and Republicans on the Senate Armed Services Committee, is the most forceful denunciation to date of the role that Rumsfeld and other top officials played in the prisoner abuse scandals of the last five years.
The document also challenges assertions by senior Bush administration officials that the most egregious cases of prisoner mistreatment were isolated incidents of appalling conduct by U.S. troops.
"The abuse of detainees at Abu Ghraib in late 2003 was not simply the result of a few soldiers acting on their own," the report says.
Instead, the document says, a series of high-level decisions in the Bush administration "conveyed the message that physical pressures and degradation were appropriate treatment for detainees in U.S. military custody."
The document aims its harshest criticism at Rumsfeld's decision in December 2002 to authorize the use of aggressive interrogation techniques at the U.S. detention facility at Guantanamo Bay, Cuba.
Although the order was rescinded six weeks later, the report describes it as "a direct cause for detainee abuse" at Guantanamo Bay, and concludes that it "influenced and contributed to the use of abusive techniques, including military working dogs, forced nudity and stress positions, in Afghanistan and Iraq."
The report also criticizes President Bush, although less harshly. In particular, it cites a presidential memorandum signed Feb. 7, 2002, that denied detainees captured in Afghanistan the protections of the Geneva Conventions, which ban abusive treatment of prisoners of war.
Bush's decision to bypass an international law that had been observed by American troops for decades sent a message that "impacted the treatment of detainees in U.S. custody," the report says.
That message was bolstered by a series of memos from the Justice Department, the report says, that "distorted the meaning and intent of anti-torture laws" and "rationalized the abuse of detainees in U.S. custody."
The Senate report represents the culmination of an 18-month investigation by the committee's staff. It is the latest, and in many respects the most comprehensive, in a series of government investigations started after photographs surfaced in April 2004 of prisoners at the U.S.-run Abu Ghraib prison in Iraq being stripped of their clothes, piled in pyramids and strapped to what appeared to be electrical wires.
Those abuses "cannot be chalked up to the actions of 'a few bad apples,' " said Sen. Carl Levin (D-Mich.), chairman of the Armed Services Committee, referring to a line used by former Deputy Defense Secretary Paul D. Wolfowitz in an attempt to downplay the scandal.
Levin said it was "both unconscionable and false" for Rumsfeld and others to blame troops and escape accountability. Even so, the report does not call for further investigation or punishment.
The findings were approved last month by the 17 committee members in attendance, indicating the report had the support of at least four of the panel's Republicans. Committee officials did not identify which senators on the 25- person panel were not present for the vote.
Among the panel's members are several GOP senators who have criticized the administration's conduct on detainee matters, including John McCain of Arizona, John W. Warner of Virginia, Susan Collins of Maine and Lindsey Graham of South Carolina.
Levin said the committee had reviewed thousands of documents and conducted interviews with more than 70 people, and received written responses from Secretary of State Condoleezza Rice.
The investigation did not focus on the CIA's treatment of detainees, or the agency's operation of a network of secret prisons.
But the inquiry turned up new information showing that the Defense Department had consulted with the CIA on interrogation matters, and that White House officials had reviewed CIA methods earlier and in more detail than previously acknowledged.
Most of the findings had been disclosed in the panel's interim reports or in other investigations. But the report released Thursday traces the origins of aggressive interrogation techniques to U.S. military survival training programs. It follows the use of coercive methods as they migrated from Guantanamo Bay to Afghanistan, then to Iraq and Abu Ghraib.
The techniques -- based on practices detailed in military courses on survival, evasion, resistance and escape, known as SERE -- included stress positions, the removal of clothing and the exploitation of phobias, including fear of dogs.