The rapid advancement of the North Korean nuclear weapons program could potentially outpace U.S. missile defense systems that need extensive innovation.

Pyongyang’s recent record-breaking intercontinental ballistic missile test, which now puts the U.S. mainland within range of a possible nuclear strike, is raising new questions about the reliability Washington's missile defense capabilities.

As it stands today, U.S. has a number of tools that can be used to intercept an ICBM that is headed for North America.

The primary line of defense is the Ground-based Midcourse Defense system that is designed to intercept a long-range ballistic missile that is targeting the U.S. homeland. These interceptors target the ICBM in space by deploying “kill vehicles” that collide with their targets before they have a chance to re-enter the atmosphere.

Other missile defense capabilities, such as Terminal High Altitude Area Defense, the Patriot, and the ballistic defense systems on Aegis ships, are also available to eliminate regional threats but have limited applications when it comes to intercepting a fast-moving ICBM.

"If North Korea launches a missile aimed at U.S. or allied territory, the fiery hot plume of the booster would be detected within one minute by U.S. satellites equipped with heat detectors,” said Dr. Bruce Blair, a former nuclear launch officer and co-founder of Global Zero. “This detection would initiate the early stage of the missile defense and the nuclear retaliation protocols.”

According to Blair, it will only take a few minutes for the two ground radar sites in Alaska to “detect and analyze the missile path, providing further cueing information to the missile defense units, which would begin to prepare to launch their interceptors designed to hit the missile in the middle of its trajectory.”

The problem, however, is that a GMD is not as reliable as many would assume, and could potentially struggle against North Korea’s next line of sophisticated nuclear capabilities.

“The U.S. missile interceptors based in Alaska and California are assessed to have a 25 percent chance of a head-on collision with the attacking missile,” Blair argued, adding that most experts “believe the true performance to be much lower.”

Although GMD’s rate of effectiveness is frequently disputed, it is no secret that the system has performed inconsistently in multiple controlled tests.

“If you look at their testing, one interceptor versus one target, they intercepted 55-56 percent of the time,” Ian Williams, the Associate Director of Center for Strategic and International Studies’ Missile Defence Project, said in an interview with the Washington Examiner.

“I think that number doesn’t reflect the reliability either,” Williams continued, stressing that the reliability improves as tests uncover malfunctions that can later be fixed.

“The problem is, we don’t test enough,” he observed. “We don’t have enough data points. We used to test twice a year and at the moment we are testing every two or three years, which is not nearly enough to really get a good sense of reliability.”

According to a Los Angeles Times report published earlier this year, a large number of GMD interceptors are susceptible to a newly discovered flaw that caused a malfunction during a system test in 2016. Officials attributed the problem to a “foreign object” that came loose in the interceptor’s internal guidance module, causing one of its thrusters to shut down.

The alarming malfunction has been a major headache for the Pentagon, that seeks to eliminate the potential error in its next generation of kill vehicles.

“There are definitely problems,” Williams told the Washington Examiner. “You have 20 [kill vehicles] which are older CE-1 model, called Capability Enhancement-1 model, which were basically put in the ground in [the mid 2000s]. ... So those are very much based on technology that was developed in mid and late 90s, really even earlier.”

The difficulty in determining GMD’s reliability and the previously documented test failures means that the U.S. has to fire more than one interceptor at each potential target. This approach, however, does not come cheap.

“One of the big issues actually is how much does it cost for you to intercept something,” Chad Ohlandt, a Senior Engineer at the Rand Corporation, told the Washington Examiner. “The bottom line is that missile defense is intercepting a missile with a missile and it always costs more than it costs the adversary to launch the missile in the first place.”

This cost distribution is precisely why the estimated 44 ground-based interceptors will fail to protect the U.S. from a serious nuclear attack from another major superpower such as Russia and China.

While the current state of the GMD will do enough to prevent any North Korean missile from reaching U.S. mainland today, Pyongyang is on a steady track of innovation, and will likely explore counter-defensive measures, such as decoys, to protect their ICBMs from incoming interceptors.

“Relative to the threat as it stands right now, I think we are in a pretty good shape,” Williams argued. “That being said, unless we can make qualitative and quantitative improvements to GMD and other stuff as well, I don’t think we will stay in good shape for very long.”

“Once North Korea perfects their ICBM program, which I think [could happen] anytime, and they start producing these things ... that’s when we are going to start having trouble keeping up with the current systems.”

Nikita Vladimirov (@nikvofficial) is a contributor to the Washington Examiner's Beltway Confidential blog. He is founder of Inside Geopolitics and also an investigative reporter for Campus Reform.

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