That familiarity, however, shouldn’t obscure that this kind of posturing is precisely the kind of rhetorical exercise that can exacerbate North Korea's insecurity and lead to deadly miscalculation—miscalculation that would, now, almost certainly expose Americans, South Koreans, and Japanese, to nuclear attack.
Unlike Trump’s off-the-cuff August promise to respond to continued threats from Kim Jong Un with “fire and fury,” his latest words were presumably the product of interagency coordination—or at least considered speechwriting reflecting policy. As a result, they reflect a bona fide U.S. position. “Rocket man is on a suicide mission for himself and for his regime,” Trump added in his speech, using his nickname-of-choice for Kim.
Why is Trump so seemingly vexed by North Korea? His speech came within weeks of Kim’s test of what was allegedly a compact thermonuclear device, which yielded an energy level an order of magnitude greater than the regime’s previous nuclear tests. Moreover, last week, for the first time ever, North Korea demonstrated its ability to fly a ballistic missile—one perhaps capable of carrying precisely the nuclear device that it claimed to have tested—to the U.S. territory of Guam. The test was also the second ballistic missile launch by North Korea to overfly Japan's territory. (North Korea had previously only launched satellite launch vehicles over Japanese territory.)
For anyone even peripherally aware of North Korea’s bellicosity, none of this is new. The Kim regime is a loathsome and serial violator of human rights, leaving its people’s interests subservient to its pursuit of what it sees as absolute security under a nuclear umbrella. But the world has dealt with all of this before. Over multiple administrations, senior U.S. officials, including presidents, have threatened to bring grievous harm to North Korea should it ever initiate a war against America or its allies. President Barack Obama, in his first summit with former South Korean President Park Geun Hye in 2013, noted that the United States would defend its ally with the “full range of capabilities available, including the deterrence provided by [its] conventional and nuclear forces.” Similarly, senior U.S. officials regularly promise an “effective and overwhelming” response to any use of nuclear weapons against the United States or its allies by North Korea.
That phrase was emphasized last year by Ash Carter and John Kerry, the then-secretaries of defense and state, respectively, and repeated recently by their successors, Jim Mattis and Rex Tillerson, in a recent Wall Street Journal op-ed outlining Trump’s North Korea policy. Clarifying that there are conditions under which North Korea would elicit its own destruction at the hands of the United States, then, has been a part of how Washington talks to and about North Korea. North Korea knows that a nuclear attack against the United States or its allies would lead to massive U.S. nuclear retaliation—total destruction, in other words. These threats, while undoubtedly gruesome, serve two important strategic ends: They reinforce deterrence against North Korea and reassure America’s allies that, if attacked, they would be backed by Washington’s full military might—including the nuclear weapons at its disposal.