Current U.S. missile defenses can counter an attack on U.S. territory by North Korea or Iran but Washington will have to boost its response capacity if those countries keep expanding their missile forces, a top U.S. admiral said on Thursday.
Admiral Bill Gortney, the officer responsible for defending U.S. air space, told a Senate panel it was "prudent" for him to assume North Korea had the ability to miniaturize a nuclear weapon and put it on an intercontinental ballistic missile that could target the United States.
"Intel community gives it a very low probability of success, but I do not believe the American people want (me) to base my readiness assessment on a low probability," he added.
Gortney's comments came at a time of heightened tensions with North Korea after Pyongyang tested a nuclear device and a long-range rocket. North Korean leader Kim Jong Un also announced Pyongyang had miniaturized a nuclear device to be fitted on an ICBM, an assertion met with skepticism elsewhere.
The U.S. missile defense system is in the process of expanding its missile interceptors to 44 from 30 by the end of 2017. Forty will be at Fort Greely, Alaska, and four at Vandenberg Air Force Base in California. The interceptors are designed to destroy a missile in space midway through its flight.
Gortney said the current U.S. missile defense system was capable of dealing with threats to either coast of the United States from "rogue" nations like Iran or North Korea. But if those countries continued to expand their missile forces, the U.S. system could fall short, he said.
"One interceptor versus one warhead in mid-course is a failing proposition because they can produce more than we can ever possibly afford to put into the ground," Gortney told lawmakers.
"We're going to need more capability to engage the threat throughout its flight, keep them on the ground, kill them on the (launch) rails, kill them in boost phase and then get more warheads in space in mid-course," he added.
Gortney said "very promising" research was under way to develop lasers and a "multiple-object kill vehicle" capable of engaging ballistic missiles at different stages. If the technologies pan out, he said the department would need additional funding to produce the defenses. (Reporting by David Alexander; Editing by Peter Cooney)