It happened some half hour before midnight on Saturday, Washington time. The US Geological Survey's Earthquake Hazards Program picked up an explosion with a 6.3 magnitude. The North Korean regime of Kim Jong-un had seemingly succeeded in testing a hydrogen device, bringing the number of nuclear tests to six so far.
President Donald Trump, kept to his usual form. Instead of urging measured calm, he expressed initial awe followed by threat. 'North Korea has conducted a major nuclear test. Their words and actions continue to be very hostile and dangerous to the United States.'
Most problematically, Trump had little patience for Seoul, which would be very much in the line of fire in any opening salvo on the peninsula. 'South Korea is finding, as I have told them,' he tweeted, 'that their talk of appeasement with North Korea will not work, they only understand one thing!'
It did not take long for observers to pick up that Trump's consternation may have been curried by other factors, not least of all his distinctly negative approach to an agreement he claims benefits South Korean companies. The South Korean-US free trade deal is set for a dramatic axing.
It is evident from this stance that neither national security advisor H. R. McMaster or Gary D. Cohn of the National Economic Council have much sway in convincing the president. Even in the shadow of a conflagration, Trump will still seek his variant of the deal.
Defence Secretary James Mattis was tasked with the onerous mission of putting flesh on the bones of the US reaction. 'Any threat to the United States or its territories including Guam, or our allies, will be met with a massive military response, a response both effective and overwhelming.'
Trump, he informed those gathered, had been briefed on 'many military options'. But Mattis must surely know that options, as he has alluded to before, vary on their feasibility. He said, in a mildly reassuring way, that the US was 'not looking to the total annihilation of a country, namely North Korea, but as I said, we have many options to do so'.
In Australia, the reactions have been far from mild. Prime Minister Malcolm Turnbull was less than reassuring, suggesting the un-testable notion that the Korean peninsula was closer to conflict than at any time since the Korean War.
"Julie Bishop suggests cutting oil supplies in an effort 'to bring unprecedented pressure to bear'. Her stress is on punishment and retribution. Such measures do less harm to the Kim regime than to the North Korean population."
The converse, if counter-intuitive argument can be made: that the Korean peninsula is being made safe from war through this aggressive pursuit of nuclear arms. This is not a view deemed acceptable to officials in Washington and Canberra but is entirely realistic given Pyongyang's aims.
Turnbull has also decided to speak on behalf of China, an odd leaf pinched from Trump's own confused book. 'The Chinese are frustrated and dismayed by North Korea's conduct, but China has the greatest leverage, and with the greatest leverage comes the greatest responsibility.' Trump prefers to word it differently: 'North Korea is a rogue nation which has become a great threat and embarrassment to China, which is trying to help but with little success.'
One prospect as irritating, perhaps more so than Pyongyang's niggling weapons program, is the flagging of a regime collapse, a dangerous situation that would see an exodus of millions into China. If that happens, it will be in no small part due to the machinations of powers that wish to see the Kim regime toppled, despite words to the contrary.
This very fact is implied by the refusal to consider negotiations while attempting that old method of economic strangulation. Australia's own foreign minister, Julie Bishop, suggests cutting oil supplies in an effort 'to bring unprecedented pressure to bear'. Her stress is on punishment and retribution. Such measures do less harm to the Kim regime than to the North Korean population. Then there is the latest suggestion by Trump: US measures to stop 'all trade with any country doing business with North Korea'.
That measure, should it be implemented strictly, will lead to a merry series of trade wars, most notably with China, given its trading relationship with Pyongyang. Whether such nightmares factor into the package of new sanctions being compiled by Treasury Secretary Steve Mnuchin remains to be seen.
The developments over the weekend suggest that Pyongyang is fortifying its diplomatic leverage, testing the resolve of powers that have come to a cul-de-sac of options. Much of that is self imposed, equating discussions with Pyongyang with appeasement.
Each nuclear test, and each ballistic weapons exercise, gives the regime an insurance policy against attack and regime change. Given that reality, the only prospect of de-nuclearisation would have to come from the most significant power in this dispute: the United States itself.
Dr Binoy Kampmark is a former Commonwealth Scholar who lectures at RMIT University, Melbourne.