NEW YORK • For months, Washington has been bracing itself for North Korea to test an intercontinental ballistic missile (ICBM), waiting to see how close it could get to the United States and how aggressively US President Donald Trump should react.
Now, it looks as if Mr Kim Jong Un, the North's 33-year-old leader, has a different plan - one intended to improve his ability to strike the United States without setting off a US military response.
Instead of going for distance, he has stepped up the testing of missiles that fly high into space - on Sunday, one reached a record height of more than 2,000km - and then plunge down through the atmosphere, mimicking the kind of fiery re-entry a nuclear warhead would undergo if fired over a much longer distance. Instead, the payload lands in waters a few hundred kilometres from North Korea's coast.
"They can simulate an ICBM warhead on this kind of trajectory," Dr David Wright, a senior scientist at the Union of Concerned Scientists, a private group in Cambridge, Massachusetts, said in an interview.
Aerospace engineer John Schilling said: "It's a kind of stepping stone." He called this relatively low-key experimentation a possible hedge against a military response.
Sunday's unobtrusive test, he said, could nonetheless "represent a substantial advance" that might bring the debut of a working ICBM closer than previously estimated.
Analysts said the test flight, if conducted on a normal rather than a high trajectory, would have travelled at least 4,000km. That is well beyond the sprawling American base at Guam, some 3,500km away. It flew for 30 minutes, much longer than other recent missile launches.
More important, it would make the flight distance the longest to date for one of the North's military missiles and thus represent a major technical success for the country
Dr Schilling called the most interesting feature of the new vehicle its potential for "demonstrating technologies and systems to be used in future ICBMs", including the KN-08 and a related long-range missile known as the KN-14.
Repeated flights of the new missile, he wrote, "would allow North Korea to conduct at least some of the testing necessary to develop an operational ICBM, without actually launching ICBMs, particularly if it includes the same rocket engines".
Overall, Dr Schilling concluded, it seems possible that North Korea with this single test flight of the new missile might have moved "closer to an operational ICBM than had been previously estimated".
US cities will not be at risk tomorrow, or any time this year, he added, since some flight testing would still have to be done with a full-scale system. Still, he added that the novel situation called for a reassessment of the North's emerging skills in making an ICBM.
The best guess of non-governmental experts puts an ICBM debut at roughly 2020. But military and intelligence officials regularly say the lack of a proven capability is different from the absence of a long- range threat to the continental United States, and they say commanders have to assume the worst, given the North's progress to date.
A functional ICBM would need a nuclear warhead that can be mounted onto a missile. The North's Korean Central News Agency (KCNA) claimed the latest test had proved its guidance and re-entry technologies, and said the rocket was "capable of carrying a large-size heavy nuclear warhead".
It was "plausible that they have made a compact warhead after five nuclear tests", Dr Hanham told AFP, but KCNA's phrasing was "interesting but vague".
Mr Michael Morell, a CIA deputy director in the Obama administration, recently told CBS This Morning: "We think they've had enough time to mate a nuclear weapon to a missile. So the threat is now."
NYTIMES, AGENCE FRANCE-PRESSE