Seven former directors of the Central Intelligence Agency on Friday urged President Obama to reverse Attorney General Eric Holder's decision to hold a criminal investigation of CIA interrogators who used enhanced techniques on detainees.

The directors, whose tenures span back as far as 35 years, wrote a letter to the president saying the cases have already been investigated by the CIA and career prosecutors, and to reconsider those decisions makes it difficult for agents to believe they can safely follow legal guidance.

"Attorney General Holder's decision to re-open the criminal investigation creates an atmosphere of continuous jeopardy for those whose cases the Department of Justice had previously declined to prosecute," they wrote. 

"Those men and women who undertake difficult intelligence assignments in the aftermath of an attack such as September 11 must believe there is permanence in the legal rules that govern their actions," the seven added. 

The letter was signed by former directors Michael Hayden, Porter Goss, George Tenet, John Deutch, R. James Woolsey, William Webster and James R. Schlesinger. 

Last month, Holder appointed special prosecutor John Durham to examine allegations that terror suspects were abused at the hands of their CIA interrogators. The highly controversial decision comes as the Department of Justice released a 2004 report from the CIA's inspector general detailing allegations of harsh interrogation practices, which Holder cited in his decision. 

The report was accompanied by conclusions that the interrogations of the detainees had yielded valuable information that had prevented further progress by terrorists.

After Holder's announcement, the White House said the president had no choice but to let the legal ramifications play out. The CIA then said it would pay for the legal expenses of the agents should they be prosecuted.

Current CIA Director Leon Panetta responded by a spokesman saying he appreciates Obama's "strong support for the men and women of the CIA," and suggested while he was in league with the sentiment of the directors, he is bound to the administration. 

"The director has stood up for those who followed legal guidance on interrogation, and he will continue to do so," said spokesman Paul Gimigliano. 

"The CIA is cooperating with the official reviews now in progress, in part to see that they move as expeditiously as possible. The goal is to ensure that current agency operations-on which the safety of our country depends-center on protecting the nation," Gimigliano added.

But in their letter to Obama, the directors wrote that not only is there a significant personal burden put on agents forced to defend themselves, "but this approach will seriously damage the willingness of many other intelligence officers to take risks to protect the country."

They added that the president has the authority to decide which legal recommendations to permit for interrogation methods, but at no time is public disclosure helpful for intelligence officers trying to protect the U.S. from further attacks.

The directors also warned that if the investigations are opened up, they fear that the assistance given to the United States by foreign intelligence agencies may jeopardize future cooperation.

"Foreign services are already greatly concerned about the United States' inability to maintain any secrets. They rightly fear that, through these additional investigations and the court proceedings that could follow, terrorists may learn how other countries came to our assistance in a time of peril," they wrote. "As a result of the zeal on the part of some to uncover every action taken in the post-9/11 period, many countries may decide that they can no longer safely share intelligence or cooperate with us on future counter-terrorist operations.