Cold War Redux?

The Cold War may be over, but the U.S. and Russia are still dead serious about spying on each other.

CBS News has learned that a senior U.S. Navy petty officer is under arrest, suspected of selling U. S. intelligence secrets to the Kremlin.

Daniel King, an 18-year Navy veteran, is being held in a Marine Corps brig in Quantico, Virginia, charged with espionage, reports CBS News National Security Correspondent David Martin. He is suspected of giving the Russians information about one of the Pentagon's most secret operations: using submarines to eavesdrop on Russian undersea communications cables.

King has spent most of his Navy career in the top-secret world of codes and communications. At the time of the alleged espionage, he was assigned to the National Security Agency, the headquarters for this country's worldwide eavesdropping operations. He worked in the office that received reports from submarines listening to Russian communications -- a high-risk operation that requires the submarines to sneak into shallow waters and tap into undersea cables.

After failing a routine lie detector test earlier this year, King admitted passing a disk full of data to the Russian embassy in 1994, apparently because he was angry at being passed over for a promotion.

It does not appear to be as serious as such Cold War cases as the Walker family spy ring, which also gave away secrets about Navy submarines, but it's further evidence the U.S. and Russia still spy on each other every chance they get.

Despite King's confession, Navy officials are not sure they'll be able to convict him. They have very little other evidence against him and King has since retracted his confession.

On Tuesday, meanwhile, Russian officials reported that a U.S. diplomat was detained for allegedly spying on Moscow. The diplomat, who was later released, was said to have been "caught red-handed," while seeking "documentary materials of a military-strategic character."

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