North Korea may see no U.S. nuclear threat: adviser

WASHINGTON (Reuters) - North Korea may have begun developing nuclear arms after deciding the United States was unlikely to use nuclear weapons to eliminate its development program, a senior Pentagon adviser said on Thursday.

"It probably is today's situation that they have developed the confidence -- perhaps misplaced confidence -- that the United States, if it were to go after their nuclear capability, likely would do so with conventional forces," said former Defense Secretary James Schlesinger.

Schlesinger, who heads a Pentagon panel charged with evaluating the U.S. nuclear mission, told reporters that he believes Pyongyang initially saw "a higher probability" that Washington would use its nuclear arsenal to wipe out a nuclear threat from North Korea.

"But as the decades have gone on, and as we have not reacted in the way they might have anticipated to their development of nuclear capabilities, they might have been encouraged to believe that they were reasonably safe from a nuclear response," he said.

Washington, concerned about the rise of nuclear weapons among rogue nations including North Korea and Iran, has used diplomatic channels to push for Pyongyang's disarmament while imposing international sanctions to prevent Tehran from developing nuclear arms.

Schlesinger said Tehran was not likely to share Pyongyang's confidence about U.S. reluctance to use nuclear force following Hillary Clinton's comment to an interviewer in April that the United States could "totally obliterate" Iran.

"Mrs. Clinton will be the secretary of state and I don't think that remark will be forgotten in Tehran," he said.

Schlesinger was U.S. defense chief during the height of the Cold War in the 1970s and served under two presidents, Richard Nixon and Gerald Ford.

He was speaking as U.S. efforts to revive a sputtering disarmament-for-aid deal with North Korea awaited the arrival of President-elect Barack Obama, who takes office on January 20.

North Korea's nuclear program dates back to at least the 1980s and according to U.S. officials has produced about 50 kg (110 lb) of plutonium.

That could be enough for about eight nuclear weapons, though some experts say Pyongyang has enough fissile material for more than a dozen bombs. No one is sure whether North Korea can make a weapon small enough to mount on a warhead.

(Reporting by David Morgan; Editing by Eric Walsh)