A collection of Bush-era national security officials have penned an open letter in “strong support” of recently revealed National Security Agency surveillance programs targeting phone company megadata and foreign Internet communications.

“We are convinced that both programs are vitally important to our national security. The Director of the NSA, Gen. Keith Alexander, has publicly attested that these programs have been instrumental in helping to prevent attacks on the United States and its allies, including the plot to bomb the New York City subway,” reads the letter.

It’s signed by former attorneys general Michael Mukasey and Alberto Gonzales, former Director of National Intelligence John D. Negroponte, former CIA director Michael Hayden and Porter Goss, former Homeland Security Secretary Michael Chertoff, and former National Security Adviser Stephen Hadley.

Diana Villiers Negroponte, a trustee at Freedom House, also signed on to the letter.

The signatories said Edward Snowden’s leaks have “seriously harmed the Nation by degrading the effectiveness of our intelligence efforts.”

“Revelations about the existence of these programs, the limitations and conditions governing the use of the acquired data and communications, and the identities of private companies that have provided access under court orders have all done irreparable damage to the national security interests of the United States. It was because of the compelling need to avoid precisely this harm to national security that the government was previously unable to explain to the public the scope of these NSA activities and the underlying legal support, though we understand that these matters have been the subject of extensive congressional oversight,” they wrote.

“Now that the existence of these programs is officially acknowledged, however, the American people can benefit from a healthy discussion about the scope of foreign intelligence collection and the governing constitutional standards. To the extent consistent with national security, this discussion should be informed by an accurate understanding of the facts.”

They acknowledge that the main question heard in response to the revelation is “How can such a large collection of data be ‘relevant’ to an authorized counterterrorism investigation, as required by section 215?”

“In reality, this use of the ‘relevance’ standard is not extraordinary or unprecedented. The same standard supports similar acquisitions of large data collections by other government agencies in regulatory investigations conducted using administrative subpoena authorities―which, unlike section 215, do not typically require court approval,” the officials write. “Denying the NSA such access to data will leave the Nation at risk. If the relevance standard of section 215 does not permit the government to acquire large data collections where necessary to preserve the data and to be able to conduct focused queries based on reasonable suspicion, our counterterrorism capabilities will be severely constrained.”

“…We believe it is fair to say that no other nation in the world conducts foreign intelligence operations with more regard for privacy and civil liberties.”

The officials urged “leaders of both parties in Washington to come together to defend these programs and to ensure their effective continuation.”

The open letter comes in response to the amendment offered to the defense appropriations bill by libertarian Rep. Justin Amash (R-Mich.), which would block funds for the NSA’s collection of phone records.