North Korea has announced that it is ready to conduct an ICBM test at any time, and the US Secretary of Defense, Ashton Carter, has stated that the US might shoot down a North Korean ICBM test if it threatened the US or its allies.
The North Korean news agency states that Pyongyang can launch an ICBM test at any time and from anywhere
“The ICBM will be launched anytime and anywhere determined by the supreme headquarters of the DPRK,” an unnamed Foreign Ministry spokesman was quoted as saying by the official KCNA news agency, using the acronym for the country’s name.
Carter is quoted, echoing Donald Trump, as saying
The United States is prepared to shoot down a North Korean missile launch or test “if it were coming towards our territory or the territory of our friends and allies,” Carter said during an appearance on NBC’s “Meet the Press.”
The “anywhere” aspect to the North Korean comment reveals that what is most likely at issue here is the flight testing of a road mobile limited range ICBM, that is the KN-08.
Carter’s comments doubtless are a reference to Japan. In 1998 North Korea tested a Taepodong-1 missile that overflew Japan, and that test was more of a good thing for ballistic missile defence than it was for the Taepodong missile programme.
The most convenient thing for North Korea is to test an ICBM that heads for the Pacific, that is overflies Japan. The Musudan medium range missile, perhaps partly due to memories of the Taepodong-1 furore, has been tested on North Korea’s west coast and the one successful test has been a lofted trajectory test which shortens the range.
From where and in what direction will the North Korean’s go if they do indeed test a limited range ICBM (most likely the KN-08)?
One option, foregoing the Japan option, would be to emulate the Unha-3 space launch vehicle flight path, that is a launch from the west coast with a flight path that heads due south.
The US would have limited options to intercept a North Korean ICBM in boost phase prior to its overflying Japan. The boost phase of an ICBM, contrary to popular or intuitive conceptions, actually takes up a short time relative to the total flight time of an ICBM launched nuclear warhead.
In the case of a North Korean ICBM targeted at the United States the burn time of the boost phase would be approximately 250 seconds, so the flight time of a North Korean ICBM test prior to overflying Japan would be even less. It has been recognised in the technical literature that the boost phase intercept options for North Korean and Iranian ICBMs don’t really exist.
The most likely means of intercept, should Carter order one, would be an Aegis based SM3 boost phase intercept given its naval platform (the SM3 system is designed for midcourse interception) but the time window is very narrow, and the Aegis launcher would need to get very close to the launch site which could be anywhere in North Korea given that the KN-08 is road mobile.
Carter doesn’t have much viable options, in short.
Should the North go over Japan, and the darn thing doesn’t explode immediately on launch, and the US does indeed attempt an intercept heaven only knows what impact that would have on strategic stability in the Korean peninsula.
The sleepwalk to catastrophe gathers pace.