The 60-page report, penned by the Union of Concerned Scientists (UCS) and seen by the Los Angeles Times, claims the US Ground-based Midcourse Defense System (GMD) is "in tatters" after years of neglect.
"Despite more than a decade of development and a bill of $40 billion, the GMD system is simply unable to protect the U.S. public,’’ the review said.
It cites US media that have been reporting failed attempts to counter a potential nuclear missile strike by Pyongyang against US towns and cities, something the North has been threatening to do on many occasions.
Scientists note that rocket interceptors, based in California and Alaska, have not been able to destroy many of mock enemy targets during heavily-scripted tests, even though the US military knew all what there was to know to detect one.
A case in point is the January flight test of a GMD interceptor which veered off course after one of its thrusters malfunctioned. This did not prevent the US Missile Defense Agency from announcing a success.