U.S. Defense officials stated Tuesday that the satellite that North Korea launched on Sunday is now tumbling in orbit and is useless. Do not take comfort from this failure. North Korea has demonstrated that it can put payloads in orbit. From this achievement it is a very short leap to aiming those payloads to impact any continent on Earth. They might not be able to aim that impact very accurately, but if you want to ignite an atomic bomb somewhere, you don't have to be very accurate.
