Stopping a North Korean missile no sure thing, US tester says

WASHINGTON — The US’s $36-billion system of ground-based interceptors can’t yet be counted on to shoot down a nuclear-armed missile aimed at the West Coast by the likes of North Korea or Iran, the Pentagon’s weapons testing office says.

The network of radar and communications combined with missiles based in California and Alaska has demonstrated only a “limited capability to defend the US homeland from small numbers of simple” intercontinental ballistic missiles, the testing office said in its latest annual report.

Despite international sanctions, North Korea has continued to test nuclear bombs and the missiles that might eventually carry a miniaturized warhead to the continental US. Meanwhile, the US has criticized Iran for conducting ballistic missile tests, although the Islamic Republic has said its program is defensive and isn’t designed to carry nuclear warheads.

The probability that the US would succeed in intercepting an incoming missile can’t be quantified with any precision “due to a lack of ground tests” supported by verified “modeling and simulation,” according to an advance copy of the assessment provided late Monday to congressional defense committees and Pentagon officials.

The testing office’s assessment is the same as its 2016 report because too few new results were generated to warrant a change, even as the threat from North Korea in particular has grown.

‘FAILURE MODES’

The office said the “reliability and availability of the operational” interceptors is also low, as the Missile Defense Agency continues to discover new flaws and “failure modes” during testing.

In response, Vice-Admiral James Syring, director of the missile defense agency, said in an interview Monday he retains “high confidence” in the system. He said the next attempt to intercept a dummy missile is tentatively scheduled for the period of April to June.

With North Korean ruler Kim Jong Un saying his country is in the “last stage” of preparations to test-fire an ICBM, incoming US President Donald Trump may face a more urgent challenge than predecessor Barack Obama in dealing with the regime. Christopher Hill, a former senior US diplomat for talks with North Korea, said on Saturday he believed Pyongyang would be able to claim with credibility within four years that it can hit the US with a nuclear weapon.

“It won’t happen!” Mr. Trump wrote recently on Twitter of North Korea’s potential test.

NEXT TEST

Success in the next US missile-defense test might bolster Mr. Trump’s vow that North Korea can be stopped. A test failure would deal him a public relations embarrassment.

The next test will attempt to shoot down a target that replicates for the first time the speed, trajectory and closing velocity of an actual ICBM, Mr. Syring said. The US will test avionics updates to the booster rocket built by Orbital ATK, Inc. that carries an improved version of a hit-to-kill conventional warhead built by Raytheon Co.

Interceptors are located at Fort Greely in Alaska and Vandenberg Air Force Base in California. The system is managed by Boeing Co.

The next interception attempt will be the first since a successful test in June 2014. Before that, though, two tests that failed in 2010 prompted an extensive effort to fix flaws with the interceptor’s warhead that Mr. Syring said have now been fixed and verified.

SAME WARHEAD

Mr. Syring said he has high confidence in the system because many of the interceptors in silos today are tipped with the same model warhead that was tested in 2014. Success in the next round would trigger the installation of eight more interceptors in Alaska, for a total of 44 — a goal set by former Defense Secretary Chuck Hagel.

“I am very confident in the systems and procedures” the US Northern Command, which operates the missile defense shield, “will employ to intercept a North Korean ICBM were they to shoot it toward our territory,” Mr. Syring said.

Laura Grego, a missile defense analyst with the Union of Concerned Scientists, said last year that none of the interception tests since 2010 have used targets representative of actual threats or complex countermeasures.

Since its inception, the system “has destroyed its target fewer than half the 17 times it has been tested, and its record is not improving over time,” she said. Since the 2004 deployment decision, “the system has a three-for-nine record,” said Ms. Grego, co-author of a July 2016 report titled “Shielded From Oversight: The Disastrous US Approach to Strategic Missile Defense.” —