INTELLIGENCE: Security Risks

Even more than the CIA, the National Security Agency prides itself on its secrecy and its security. Headquartered behind an electrified triple barbed-wire fence at Fort Meade, Md., NSA is the agency that formulates U.S. codes and tries to crack enemy codes. Behind the barbed-wire curtain last week hummed an unaccustomed turmoil of alarm: two NSA employees had disappeared.

Bernon F. Mitchell, 31, and William H. Martin, 29, both mathematicians doing statistical code analysis at NSA, went off June 24 on vacation together as usual. Ever since they first met as naval communications technicians in Japan in 1953, they had been close companions. Last Christmas they went to Cuba together.

Thinking back on their past behavior, NSA conceded that it was a bit odd. Martin, son of an Ellensburg, Wash. accountant, made a hobby of hypnotizing people. Mitchell, son of a Eureka, Calif. lawyer, was under psychiatric treatment.

When they left Washington together, Mitchell and Martin told their boss that they were off to the West Coast to visit their parents. Instead, they went to Mexico City, checked in at a cheap hotel, told the clerk that they would be staying about two weeks. Next morning they abruptly checked out, later boarded a plane for Havana. Last week the Defense Department glumly announced that from Cuba the pair had apparently "gone behind the Iron Curtain," and added, as reassuringly as it could, that the two men did not know any important secrets.