U.S. Has a New Plan to Fight North Korea: Shoot Down Kim Jong Un's Missiles As They Launch, but Can It Work?

Secretary of Defense Jim Mattis told Congress Thursday that the U.S. military is developing the technology to shoot down North Korean missiles as they take off.

Arms experts say the technology would greatly improve the U.S.'s ability to fend off a nuclear attack from North Korea, but it probably won't be ready for another 10 to 15 years.

"What [Mattis] is referring to is boost phase directed energy, so the idea is to have a laser on a drone, have the drones hovering in international airspace, and then once a missile is launched we zap it with a laser," Matthew Kroenig, an expert on national security and arms control at the Atlantic Council, told Newsweek.

"We have directed energy interceptors on ships, so the basic technology is proven. But it won't be until 2025 or so that this will be a real capability," Kroenig added.

For now, the U.S. military is trying to develop ways to make the laser technology, known as directed energy, powerful enough to destroy a ballistic missile but light enough to fit on an aircraft that can fly at high altitudes, experts note. Around a megawatt of power is needed to destroy a ballistic missile as it's taking off, analysts say, and generally the more powerful lasers are, the heavier.

"The military is looking at UAVs [unmanned aerial vehicles] and how can we use these predator drones and reaper drones in a missile defense capacity, mounting directed energy, essentially lasers that would fly at high altitude, above the weather," Ian Williams, an expert on missile defense and deterrence at the Center for Strategic and International Studies, told Newsweek.

The U.S. already has the technology to theoretically destroy a ballistic missile as it's taking off, using more traditional missile technology. But the process requires more resources, and there are still questions about whether traditional missiles are fast enough to destroy an intercontinental ballistic missile (ICBM) on time.

"It's a question of how many drones we want to put up, and can we get it up close enough to fire. You would need to be right over the boosting missiles. You would have to get in their airspace and get there in advance of the launch," Williams said. "A laser moves at the speed of light, so as long as you're in range you can hit the target, but with a kinetic missile there is a window. And there is a debate about whether the window is too small."

In Pyongyang's Kim Il Sung Square on December 1, 2017, North Korean soldiers attend a mass rally to celebrate the North's declaration in November that it had achieved full nuclear statehood. Kim Won-Jin/AFP/Getty Images

North Korea is in the process of developing a nuclear weapon that is small enough to fit onto an ICBM. Experts disagree on how long it will take the rogue regime of Kim Jong Un to fit a nuclear warhead onto a missile, but most analysts say that Pyongyang already has a missile capable of reaching anywhere in the U.S.

President Donald Trump says he will meet with Kim in May to discuss a path toward North Korea's complete denuclearization, and experts say the U.S. military's advanced technology could help sway the direction of the talks.

"It's probably not one of the first factors driving negotiations. North Korea is thinking about whether there will be a near-term military strike, if China will be on their side during the negotiations, about sanctions," Kroenig said. "If anything, [U.S. laser technology] could help the ongoing negotiations. I think Kim Jong Un is rational and thinking about the costs and benefits. This will provide him incentive to get a good deal before we have that capability."

Others, however, argue that Mattis's comments could prompt North Korea to increase spending on its nuclear program.

"Generally, missile defenses have not been shown to discourage states from pursuing nuclear and missile technologies," Scott LaFoy, a satellite imagery analyst who focuses on North Korea, told Newsweek. "Functional missile defenses will definitely cause the North Koreans to spend more money, as they would likely build additional missiles to ensure they could overwhelm U.S. defenses."