The National Security Agency's assertion that it obeys the law [letters, Dec. 7] in its surveillance operations would be more comforting if its counsel had been more candid about the loopholes and limits of existing legal restrictions in this increasingly interconnected age. There are no laws restricting NSA surveillance of individuals, including Americans, overseas. And while the NSA adopted internal regulations 20 years ago restricting its intentional targeting of Americans' overseas communications, those regulations do not meet constitutional standards--such as requiring a warrant prior to any surveillance.

Moreover, despite its counsel's protestations that the NSA does not ask other nations to do what it legally cannot, the NSA is free, with its partners in England and elsewhere, to vacuum up millions of overseas communications, a practice that would be illegal inside the United States. It is free, using keyword searches, to then read the e-mail and phone calls of Americans overseas--as long it does not "target" individual Americans in doing so.

Equally troubling is the fact that no law prevents the agency from targeting overseas communications by non-Americans, whether they be Russian or Egyptian human rights activists labeled terrorists by their governments or individuals suspected, rightly or wrongly, of criminal activity. Such surveillance, conducted in secret and without probable cause, is wholly unrestricted under existing law. Unlike Cold War surveillance of the Soviet Union, NSA eavesdropping on such individuals violates their universally guaranteed human rights to privacy and due process of law.

While the United States urges international respect for human rights, it is time for a public debate about how the NSA operates and what rules are needed to protect the civil liberties of all.

KATE MARTIN

Washington

The writer is director of the Center for National Security Studies.