During an interview with Sean Hannity last week, President Donald Trump reassured Americans that “we build the greatest military equipment in the world” and that “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.” In a way, Trump’s comments are unsurprising; aggression, confidence, and bravado are the hallmarks of the strategy Trump has thus far tended to employ when dealing with North Korea. Unfortunately, they also suggest he has a rose-colored view of a missile-defense system that is beset by problems and functionally unreliable.
To begin with, American missile defense is nowhere near 97 percent effective. The overall integrated network consists of four main systems: Ground-Based Midcourse Defense (GMD), Aegis Ballistic Missile Defense (Aegis BMD), Terminal High Altitude Area Defense (THAAD), and Patriot Advanced Capability-3 (Patriot PAC3). Since 2001, these four combined have intercepted 76 of 93 targets, an 82 percent success rate.
But Patriot PAC-3 interceptors wouldn’t be employed against North Korean ICBMs; they’re mostly used to counter short-range, tactical missiles. That leaves THAAD, Aegis BMD, and GMD. And when considering just these three, the rate drops to 79.6 percent. Even more worrying is the success rate of the GMD by itself. Of all three, the GBM is the system theoretically most effective for deterring North Korean ICBMs. But it works only 55.5 percent of the time in tests, and since December of 2008, it’s successfully engaged only two out of five test missiles.
What’s more, even if the entire integrated missile-defense network were 100 percent effective in tests, there would be reason to temper our optimism. In an interview with Wired in May, the former head of test and evaluation at the Pentagon, Philip Coyle, explained that tests are “scripted for success.” In other words, success is the assumed outcome; the Missile Defense Agency (MDA) gives the interceptors significant information about the target before the test — what it looks like, when it should arrive — and omits decoys and countermeasures that would most likely be deployed with a North Korean missile. “What’s been surprising to me,” Coyle told Wired, “is that they have failed as often as they have in spite of that.”
As for Trump’s claim that two interceptors increase the chance of success to 100 percent, he is half correct. He’s right that multiple interceptors increase the likelihood of a successful intercept. Given the low success rate of its tests, the Pentagon’s likely operating procedure is to order more than one interceptor to target a North Korean ICBM. But two wouldn’t do it, and even four wouldn’t be perfect. As Laura Grego, a physicist at UCS and an expert in ballistic-missile defense, wrote in All Things Nuclear last week, four interceptors would lead to “a 6 to 13 percent chance that the warhead gets through.” In other words, four-on-one targeting has a theoretical effectiveness of 87 to 94 percent, still neither 97 nor 100 percent.
Which is to say that the U.S. missile-defense network is unreliable and that Trump has claimed otherwise. It is, of course, possible to consider Trump’s statements part of a larger military strategy. A boast conveying such a degree of strength communicates to the world that America isn’t worth attacking: If Kim Jong-Un were prepared to fire a missile at America tomorrow, hearing that the U.S.’s missile-defense system guarantees a 3 percent chance of success would logically be a sufficient deterrent, especially when he knows the retaliation would be swift and comprehensive. Nevertheless, even this approach could be risky. Giving the impression of an impenetrable missile-defense system might instead encourage North Korea to back off only temporarily while the Kim regime takes time to make its missiles more effective.
First, Trump needs to understand that our missile-defense program desperately needs more funding, and that his comments work contrary to securing such funding — a goal he has made clear he shares — by instilling false confidence in the program. President Barack Obama’s disbelief in missile defense led to several drastic funding cuts during his administration. He reduced the program’s budget by $3.7 billion from George W. Bush’s proposed budget for the fiscal years 2010–2012. He cancelled the installation of 14 additional GMD interceptors. And he ended all boost-phase defense programs. These cuts set the Pentagon back by several decades and have resulted in the system’s current inchoate status. A Republican Congress shouldn’t be an obstacle to increased support for missile defense, but Trump’s comments could be.
Second, and far more critically, Trump’s comments suggest he believes that a missile attack isn’t a real threat. As Kingston Reif, who is a director at the Arms Control Association, wrote in May, this delusion could lead Trump to believe he can combat North Korean aggression “without having to worry about a potential . . . nuclear response.” Essentially, Trump’s lack of a working knowledge of missile defense may lead to a military decision based on misinformation.
Trump often forgets that he speaks on a world stage, as the commander-in-chief of the world’s most powerful military, which is rapidly approaching conflict with a hostile, nuclear-armed foreign power. His statements now have much deeper implications than they did during the campaign, and he should be more careful before making ill-informed boasts about American missile defense in the future.
— Philip H. Devoe is a Collegiate Network Fellow with National Review.