We probably have a small window of opportunity because warhead and re-entry vehicle integration with the ICBM isn't complete yet, and probably won't be, but that's small comfort to the South and Japan who are in range with the less advanced IRBM and SRBM systems they have now.
But the article does point out one thing I've been saying, one of North Korea's biggest threats is China itself. And long-term at least, the nuclear/MAD deterrence is as much for China as it is for the U.S. The entire thing goes unspoken as an elephant in the room when it comes to the North's and China's relationship, but the North Koreans/Jongs know full well that despite China's patronage in the past, that China has been willing to invade or war with other neighboring nations, even Communist ones if it suits their interests, like the invasion/war with Vietnam, over Vietnam invading Burma to depose the Khmer Rouge, who's genocide was getting too sporty even for their fellow Communists, and China retaliating by invading Vietnam.
And the whole nuclear program is a calculated risk that they can get it up and running faster than China can finally decide "enough is enough" and try for regime change in the DRPK.
Yes, China pretty much demands that they have the North as a buffer-state between them and the South and U.S. forces, but it needs to be a stable nation they can control or at least trust. And right now they can't.
