Trump may be dangerously overconfident in US missile defenses against North Korea

President Donald Trump gave an interview to Fox News' Sean Hannity on Wednesday night where he discussed the North Korean crisis and perhaps a dangerous overconfidence in US missile defenses.

Asked about the threat North Korea's nuclear and missile programs pose to the US, Trump said the issue should have been handled in previous administrations, and praised China for its cooperation with a US-led sanctions push against Pyongyang.

But Trump also seemed to put faith in a not-so-reliable element the US's defense against North Korea.

"We build the greatest military equipment in the world," Trump told Hannity. "We have missiles that can knock out a missile in the air 97 percent of the time, and if you send two of them, it's going to get knocked out."

The exact missile defense system referenced by Trump remains unclear, but the US only has one program designed to protect the mainland from intercontinental ballistic missiles (ICBM): The ground-based midcourse defense (GMD).

According to Lauren Grego, the senior scientist in the Global Security Program at the Union of Concerned Scientists, the GMD's "single shot kill probability" for an ICBM is unknown. Even in "optimistic conditions," Grego gives the GMD about a 50 percent chance of knocking out a single ICBM. By firing four missile interceptors for every incoming ICBM threat, that chance climbs to 94 percent, Grego calculated.

Grego's estimates sit well with the GMD's track record, made public by the Missile Defense Agency.

The US does have other missile defense systems with records closer to 97 percent, but they do not defend the US mainland in its entirety or defend against ICBMs.

Trump's overconfidence may signal a dangerous dismissal of the very real threat posed to the US by North Korea's nuclear-tipped ICBMs in development - or it may be part of a deliberate strategy.

Tong Zhao, a leading North Korea expert with the Carnegie's Nuclear Policy Program in Beijing, told Business Insider that nuclear nations have to assume the worst of their enemies' capabilities. Basically, North Korea would never fire on the US unless it could be absolutely sure its missiles would achieve their intended purpose.

But, "the US will never allow [North Korea] to feel their deterrent is credible," Zhao said. One way the US will do that is by continued investment in missile defenses and talk of cyber capabilities that can wipe out its command structure.

Even China, which has had a credible nuclear deterrent for decades, fears the US's THAAD missile defense systems in South Korea could leave them defenseless to a US attack.

But while a bluff from Trump could deter North Korea, Zhao points out that Pyongyang's feeling of insecurity will likely breed more and more dangerous nuclear and missile testing and deepen the stalemate between the two countries.