The North’s young leader, Kim Jong Un, faced a range of troubles, they assured the new administration, giving Trump time to explore negotiations or pursue countermeasures. One official who participated in the early policy reviews said estimates suggested Kim would be unable to strike the continental United States until 2020, perhaps even 2022.
Kim tested eight intermediate-range missiles in 2016, but seven blew up on the pad or shattered in flight — which some officials attributed partly to a U.S. sabotage program accelerated by President Barack Obama. And while the North had carried out five underground atomic tests, the intelligence community estimated that it remained years away from developing a more powerful type of weapon known as a hydrogen bomb.
Within months, those comforting assessments looked wildly out of date.
At a speed that caught U.S. intelligence officials off guard, Kim rolled out new missile technology — based on a decades-old Soviet engine design, apparently developed in a parallel program — and in quick succession demonstrated ranges that could reach Guam, then the West Coast, then Washington.
And on the first Sunday in September, he detonated a sixth nuclear bomb. After early hesitation among analysts, a consensus has emerged that it was the North’s first successful test of a hydrogen weapon, with explosive force some 15 times greater than the atomic bomb that leveled Hiroshima.
The CIA and other U.S. intelligence services had predicted this moment would come, eventually. For decades, they accurately projected the broad trajectory of North Korea’s nuclear program. Yet their inability to foresee the North’s rapid strides over the past several months now ranks among the United States’ most significant intelligence failures, current and former officials said in recent interviews.
That disconnect — they saw it coming, but got the timing wrong — helps explain the confusion, mixed signals and alarm that have defined how Trump’s untested national security team has responded to the nuclear crisis.
In an interview, Lt. Gen. H.R. McMaster, Trump’s national security adviser, acknowledged that Kim’s race to the finish line — a bid to establish the North as a nuclear power before any negotiations begin or sanctions take a more punishing toll — “has been quicker and the timeline is a lot more compressed than most people believed.”
As a result, he argued, “we have to do everything we are doing with a greater degree of urgency, and we have to accelerate our own efforts to resolve the issue short of conflict.”
Senior intelligence officials said they began investing more heavily in acquiring information on North Korea’s weapons program in 2012, reaping benefits over the past two years. But they acknowledged they made two key assumptions that proved wrong.
They assumed that North Korea would need about as much time to solve the rocket science as other nations did during the Cold War, underestimating its access to both advanced computer modeling and foreign expertise. They also misjudged Kim, 33, who took control of the dynastic regime in late 2011 and made the weapons program more of a priority than his father or grandfather did.
Obama warned Trump during the transition a year ago that North Korea would pose the most urgent national security threat, and almost immediately the newly installed president began repeating, publicly and privately, that he inherited “a mess” in North Korea because his predecessors did not do enough.
Former officials in the Obama administration dispute that. But some concede that the intelligence community’s flawed assessment of the North’s progress meant there was less pressure to bolster missile defenses, more vigorously enforce sanctions or consider stepped-up covert action.
It is not clear that even with more advanced warning the Obama or Trump administrations would have been able to slow Kim’s progress.