A North Korean test of an ICBM, confirmed overnight by U.S. officials, is a momentous step forward for Pyongyang as it works to build an arsenal of long-range nuclear-armed missiles that can hit anywhere in the United States. The North isn't there yet — some analyst suggest it will take several more years to perfect such an arsenal, and many more tests — but a successful launch of an ICBM has long been seen as a red line, after which it would only be a matter of time — if the country isn't stopped.