Watch a US defense test successfully shoot down a missile

A credible way to intercept intercontinental ballistic missiles has been a cornerstone of American defense thinking since the early days of the Cold War. With renewed ballistic missile threats from China and North Korea, the need for a reliable way to intercept incoming ballistic missiles on their way to the US mainland was renewed.

But the most recent test shows more promise for a new interception system than at any time in U.S. military history, with the system successfully intercepting an incoming test ICBM as it was designed to do.

The test missile was an ICBM launched from the Reagan Test Site on Kwajalein Atoll in the Marshall Islands, some 4,000 miles away from the United States. The interceptor missiles were launched from California's Vandenberg Air Force Base via an underground missile silo. This test was a "salvo" test, which means multiple missiles were fired at the same incoming missile to increase the chances of destroying it.

"The system worked exactly as it was designed to do," said Air Force Lt. Gen. Samuel A. Greaves, director of the Missile Defense Agency. The test result "demonstrates that we have a capable, credible deterrent against a very real threat."

But not everyone agrees.

In this photo provided by the Missile Defense Agency, the lead ground-based Interceptor is launched from Vandenberg Air Force Base, Calif., in a "salvo" engagement test of an unarmed missile target Monday, March 25, 2019. In the first test of its kind, the Pentagon on Monday carried out the "salvo" intercept of an unarmed missile soaring over the Pacific, using two interceptor missiles launched from underground silos in southern California.

(Missile Defense Agency)

The Union of Concerned Scientists says the Ground-based Midcourse Defense system that launched the test is more akin to "hitting a bullet with a bullet," and the system is hugely expensive, ineffective, and offers no proven capability to protect the United States. It goes on to note the GMD in its current state was fielded before any tests were conducted on the system and two-thirds of its intercepts fail. The Union calls the system wasteful and calls on the government to figure out another strategy for missile defense.

The Pentagon will spend .4 billion on missile defense, including the GMD, in the year 2020.

"Success is better than failure, but because of the secrecy I have no idea how high the bar was set," said Laura Grego of the Union of Concerned Scientists. "How realistic was the test? The Pentagon had a very long way to go to demonstrate the system works in a real-world situation."

A ballistic missile test-fired from Meck Island in the Kwajalein Atoll.

The United States also uses space-based and sea-based missiles in its missile defense network. These systems were also used to track the successful test intercept.

"This was the first GBI salvo intercept of a complex, threat-representative ICBM target, and it was a critical milestone," Lt. Gen. Greaves said in a released statement.