N Korean missiles may one day threaten US

North Korea's successful long-range rocket shot raised a nightmarish specter for Americans: that one day its longtime adversary could fire a nuclear-tipped missile into the US mainland. But North Korea still has far to go to make that threat a reality.

Experts say the North still faces major technical hurdles. Wednesday's launch showed it can fire a rocket into space, but it has not worked out how to make a projectile return to Earth and hit a target. Nor has it mastered how to put a nuclear warhead on a missile. Even if it solves those problems, a giant rocket would be vulnerable to a pre-emptive attack.

That's little consolation for US officials who say North Korea is progressing technologically, and unless that progress is checked, it's only a matter of time before the North has the ability to threaten America and elsewhere with a long-range ballistic missile.

There's still time to negotiate, and Washington will be pressing China, the North's main ally, to get Pyongyang to play ball. But negotiating North Korea's disarmament in return for much-needed aid will prove tough if the North's totalitarian leadership — ensconced since the Korean War six decades ago — views its weapons of mass destruction as key to its survival.

Six-nation talks on the North's nuclear program, also including China, the US, Russia, South Korea and Japan, have been stalled since 2009, and the Obama administration's effort last year to kick start the process by offering food aid in return for nuclear concessions collapsed when Pyongyang attempted a satellite launch in April.

That launch attempt failed, like the three other launches of three-stage rockets that had proceeded it since 1998, leading to skepticism that the impoverished country, which subject to tough international sanctions, had the wherewithal to succeed. But Wednesday's launch managed to send a small communications satellite into orbit, prompting celebrations in Pyongyang.

In 2010, US Secretary of Defense Robert Gates warned that within five years the North could develop an intercontinental ballistic missile capable of reaching the United States, and Wednesday's launch suggests the North is on track for that, said former U.S. defense official, James Schoff, now an expert on East Asia at the Carnegie Endowment for International Peace.

But he and other experts say the North must still surmount tough technical barriers.

"It's worth keeping in mind that even though this launch worked, North Korea has no confidence in the reliability of the rocket, which undermines its utility for military purposes," said David Wright at the Washington-based Union of Concerned Scientists.

Wright says the Unha-3 has a potential range of 8,000 to 10,000 kilometers (4,970 to 6,210 miles), which could put Hawaii and the northwest coast of the mainland United States within range. But the satellite it mounted on the rocket weighs only 50 kilograms (110 pounds) — about a tenth the weight of a nuclear warhead. The North would also have to develop a heat shield for a missile so it could withstand the extreme heat and pressure of a descent back through the Earth's atmosphere. It would also need a guidance system to enable it to hit a target.

"Those are pretty serious tasks," Wright said.

Another key technical challenge would be to miniaturize a nuclear warhead to fit on a missile. The North Korea conducted nuclear tests in 2006 and 2009, and probably has enough plutonium for a half-dozen or more bombs, but would will have to do more testing to advance its warhead designs.

Even if it achieves all that, experts say a liquid-fueled rocket like the 32-meter (105-foot) -tall Unha-3 on which a ballistic missile could be based takes days to assemble and hours to fuel. That would be vulnerable to attack in a pre-emptive airstrike, compared to more mobile solid-fueled missiles developed by the US and Soviet Union which are more easily concealed and ready to launch within minutes.

But Victor Cha, a former White House director for Asia policy, warned there has been an unspoken tendency in the United States to regard North Korea as a technologically backward and bizarre country, underestimating the strategic threat it poses.

"This is no longer acceptable," he wrote in a commentary, noting Wednesday's launch makes North Korea one of the only non-US allied countries outside of China and the Soviet Union to develop long-range missile technology that could potentially reach the United States.

North Korea portrayed the launch as a success for its peaceful space program, but it violates U.N. Security Council resolutions that forbid North Korea from such rocket launches as the technology can be used for ballistic missiles. The U.S. and allies will now be pressing for tighter sanctions against Pyongyang, although it remains to be seen if they can win China's support.

"This launch is about a weapons program, not peaceful use of space," State Department spokeswoman Victoria Nuland said.

North Korea already poses a major security threat to its East Asian neighbors. It has one of the world's largest standing armies and a formidable if aging arsenal of artillery that could target Seoul, the capital of South Korea. Nearly 30,000 U.S. forces are based in South Korea, a legacy of the 1950-53 Korean War that ended with an armistice not a formal peace treaty.

The North's short-range rockets could also potentially target another core US ally, Japan.

Darryl Kimball, executive director of the nongovernment Arms Control Association, said those capabilities, rather than its future ability to strike the US, still warrant the most attention. He said the launch of the Unha-3 was worrisome and would provide valuable information for the North in its missile development, but would not change the balance of military power in the region.

Follow Emirates 24|7 on Google News.