The US is pushing ahead with expansion of the nation’s homeland ballistic missile defense (BMD). The effort enjoys strong bipartisan support in Congress and among experts. Many allies place a high value on BMD cooperation with the United States. However, there are ample reasons to question the efficiency of US missile defenses, especially the capability to protect against intercontinental ballistic missiles (ICBMs).

“We have missiles that can knock out a missile in the air 97% of the time,” President Donald Trump said in his interview with Fox News on October 11, adding “and if you send two of them, it’s going to get knocked down.” He was talking about the threat coming from North Korea to be repelled by the Ground-Based Midcourse Defense (GMD) in Alaska and California – the $40 billion project administered by the Missile Defense Agency (MDA).

The US military conducted the first-ever missile defense test involving a simulated attack by an intercontinental ballistic missile in May. The ICBM-type target was fired from the Kwajalein Atoll in the Marshall Islands toward the waters just south of Alaska. The mission was to prepare for countering an intercontinental missile launched by North Korea. The Missile Defense Agency (MDA) described the test as an “incredible accomplishment”. According to Vice Admiral Jim Syring, director of the agency, “This system is vitally important to the defense of our homeland, and this test demonstrates that we have a capable, credible deterrent against a very real threat.” The assessment appears to be exaggerated as the test was not conducted in a realistic environment.

The next test of the GMD system is scheduled for late 2018 and, for the first time, will involve firing two interceptors against one ICBM target. It makes unsubstantiated the president’s affirmation that two interceptors are enough to knock out a North Korean missile as no such tests have been conducted so far.

The US currently deploys 36 interceptors – 32 at Fort Greely, Alaska, and four at Vandenberg Air Force Base, California. By the end of 2017, there will be 44 deployed GBIs. A majority of the interceptors use the CE-I variant of kill vehicle that has scored only two successes in four tests. At least ten interceptors are to be equipped with the CE-II Block I vehicle, which has had two successful intercept tests in three tries.

It is generally believed that it takes at least four-five interceptors to hit the target. It means President Trump is off base saying the hit probability is 97%. Prior to the ICBM test, the GMD system had successfully hit its target in only ten of 18 tests since 1999. A success rate is about 56%, not 97%. But even 56% is almost certainly an overstatement, given the less-than-realistic nature of the tests.

A success rate for four-five interceptors per target may be 97% but the possibility that each successive interceptor’s chance of successful kill might not be independent of the previous one, due to correlated factors such as design shortcomings, leading to a lower overall success rate. Nevertheless, President Trump believes each interceptor has a single-shot probability of kill (SSPK) for a given interceptor of 97% (rather than 56%).

According to the Washington Post, “No single interceptor for ICBMs has demonstrated a 97-percent success rate, and there is no guarantee using two interceptors has a 100-percent success rate. Moreover, the military’s suggestion that it could achieve a 97-percent success rate with four interceptors appears based on faulty assumptions and overenthusiastic math. The odds of success under the most ideal conditions are no better than 50-50, and likely worse, as documented in detailed government assessment.”

Joe Cirincione, the President of Ploughshares Fund and the author of Nuclear Nightmares: Securing the World Before It Is Too Late, investigated anti-missile programs for almost 10 years as professional staff on the House Armed Services and Government Operations Committees. He believes that “If people took a close look at just one of these interceptor tests, they would likely conclude, as I did, that the tests bear little resemblance to real-world conditions.”

If North Korea fired an ICBM – or multiple ICBMs – at the United States, the GMD with its Ground-Based Interceptors (GBIs) is only one system that could take a shot at intercepting and destroying the warhead outside the earth’s atmosphere in midcourse flight. Other missile defense systems such as THAAD and Aegis are in no position to hit ICBMs as they’re designed for other classes of targets.

With only one test against an ICBM, the MDA is not even close to demonstrating that the system works in a real-world setting. The GMD systems have not yet been tested in the range of conditions under which it is expected to operate. No tests have been conducted at night or against complex countermeasures, such as electronic countermeasures and decoys. The tests are always rigged because the intercept team knows the timing and trajectory of the incoming missile. But even the scripted tests have often failed. What has been done so far is insufficient to demonstrate that an operational BMD capability really exists. […]

Philip Giraldi, a highly respected expert and the Executive Director of the Council for the National Interest, believes that the American people are being fooled by the administration, which tries to make them think that a nuclear war is thinkable. According to him, “If that is the message being sent by the White House, it would encourage further reckless adventurism on the part of the national security state.” Mr. Giraldi hit the nail right on the head. The GMD effort creates a dangerous illusion that a victory in a nuclear conflict is achievable and no money should be spared to spur the implementation of the MDA plans. In reality, the US defense industry is the only benefactor while the taxpayers throw money into the drain. The result: further erosion of arms control and reduced security.