WASHINGTON // North Korea's newly demonstrated missile muscle puts Alaska within range of potential attack and stresses the Pentagon's missile defences like never before. Even more worrisome, it may be only a matter of time before North Korea mates an even longer-range ICBM with a nuclear warhead, putting all of the US at risk.
The Pentagon has spent tens of billions to develop what it calls a limited defence against missiles capable of reaching US soil. The system has never faced combat or been fully tested. The system succeeded May 30 in its first attempted intercept of a mock ICBM, but it has not faced more realistic conditions.
US president Donald Trump said on Thursday he was considering a "pretty severe" response to North Korea's intercontinental ballistic missile test, even as China appealed for a scaling down of rhetoric.
Tuesday's launch marked a milestone in Pyongyang's decades-long drive to threaten the US mainland with a nuclear strike, posing a thorny policy challenge for Mr Trump, who is at loggerheads with Beijing over how to handle the North Korean leader, Kim Jong-un.
"I call on all nations to confront this global threat and publicly demonstrate to North Korea that there are consequences for their very, very bad behaviour," Mr Trump said during a visit to Warsaw.
The European Union and Japan on Thursday joined Washington's push for tougher sanctions against Pyongyang to put pressure on Mr Kim's regime.
Although Russia and China have long been capable of targeting the US with a nuclear weapon, North Korea is seen as the bigger, more troubling threat. Its opaque, unpredictable government often confounds US intelligence assessments. And Mr Kim has openly threatened to strike the US, while showing no interest in nuclear or missile negotiations.
"We should be worried," said Philip E Coyle III, a former head of the Pentagon's test and evaluation office. North Korea's latest success "shows that time is not on our side", he said.
US officials believe North Korea is still short of being able to miniaturise a nuclear warhead to fit atop an intercontinental missile. And it is unclear whether it has developed the technology and expertise to sufficiently shield such a warhead from the extreme heat experienced when it re-enters Earth's atmosphere en route to a target.
A Pentagon spokesman, Navy Capt Jeff Davis, said on Wednesday that "we've still not seen a number of things that would indicate a full-up threat", including a demonstrated ability to mate a nuclear warhead to an ICBM. "But clearly they are working on it. Clearly they seek to do it. This is an aggressive research and development program on their part."
Capt Davis said the US defensive system is limited but effective.
"We do have confidence in it," he said. "That's why we've developed it."
The Trump administration, like its recent predecessors, has put its money on finding a diplomatic path to halting and reversing North Korea's nuclear programme. While the Pentagon has highly developed plans if military force is ordered, the approach is seen as untenable because it would put millions of South Korean civilians at risk.
But diplomacy has failed so far. That is why US missile defences may soon come into play.
