Debris from North Korea's failed satellite launch was tracked by U.S. intelligence agencies nearly 4,000 miles into the Pacific Ocean - a far greater range than earlier estimates and a sign it could hit Alaska or Hawaii with a small warhead.
"This further underscores a major intelligence failure in terms of what is going on in the world about growing missile threats," said Rep. Curt Weldon, Pennsylvania Republican and chairman of the House National Security subcommittee on military research and development.
Mr. Weldon said in an interview that the spread of debris from the Taepo Dong missile that far into the Pacific is a sign that North Korea right now may have the capability of hitting parts of the noncontiguous United States.
Pentagon spokesman Ken Bacon said North Korea's attempt to put a satellite in orbit is a troubling development.
"The capability that allows them to launch satellites is the capability to project payloads over a longer range, and we consider that to be worrisome," Mr. Bacon told reporters.
The satellite launch was less worrisome than testing a warhead over long distances "point to point," he said. "But the fact of the matter is that it does display some enhanced capability, or an attempt to develop an enhanced capability, on the part of the North Koreans," he said.
The solid-fueled third stage may have a range of between 2,408 miles and 3,720 miles, Mr. Bacon said. Initial estimates put the missile's range at about 1,000 miles.
A U.S. official familiar with intelligence assessments of the Aug. 31 test launch said the satellite broke into pieces several seconds before reaching orbit, indicating that a warhead "could potentially have gone that far."
Mr. Bacon and other administration spokesmen sought to play down the new missile development. He said the North Koreans are still facing technical hurdles for a long-range missile, such as having enough propellant in the third stage and in developing the capability to shield a warhead from the effects of extreme heat during re-entry into the atmosphere.
However, Henry Sokolski, a former Pentagon proliferation official during the Bush administration, said the administration was missing the point of what he views as a dangerous new development.
"This is a totally new threat. It looks like [the North Koreans] leapfrogged from a two-stage missile to a three-stage missile," Mr. Sokolski said. "What is alarming is the fact that they are working on a three-stage missile at all."
Until the test, the intelligence community believed North Korea's missile program was based on single-stage missile technology, he said.
The test-firing from a range in North Korea over northern Japan was closely monitored by U.S. and Japanese surveillance ships and aircraft and by National Security Agency electronic-eavesdropping satellites.
But the fact that North Korea had a space-satellite program caught U.S. intelligence agencies off guard, said U. …