North Korea's announcement that it had successfully tested a hydrogen bomb was met with shock and surprise around the world - but there have been months of indications that something in just this vein was on the way.
Kim Jong-Un's visit to Phyongchon Revolutionary Site near Pyongyang in December 2015 would have passed with little comment were it not for the young leader's passing mention that his state was ready to detonate a hydrogen bomb. North Korea's nuclear arsenal, what it calls its "treasured swords," has only briefly and tenuously been demonstrated, and when Kim made this unexpected announcement, the outside world was sceptical that Pyongyang had really mastered this complicated and demanding technology.
The world is still grappling with the geopolitical and diplomatic fallout from the test, and the technical plausibility of the claim is already being called into question. But whatever the truth behind this rather shocking announcement, it fits very neatly into North Korea's developmental and political agenda.
While Kim Jong-un's 2016 New Year message was hardly revealing, it was certainly true to form. Among the calls to develop the metal industry, produce more electricity and make sure that North Koreans "enjoy the highest quality of civilization" was material focused on military capability.
In retrospect, the statement may have telegraphed precisely these latest announcements. Perhaps this stepped-up nuclear capability was what Kim meant when he called again for North Korea's defence industry to be placed on a "scientific footing," or to "develop and produce a greater number of various means of military strike of our own style."
But the message also reiterated that 2016 is a "significant year" because the Seventh Workers Party Congress will be held - and that may explain rather more about why this test was announced now.
The last Party Congress of the Workers Party of Korea, its sixth, was held in October 1980. It sought to navigate some of the disruptions and drag factors created by decades of unsuccessful central economic planning, and it's remembered as a watershed moment for its abandonment of many of the most dramatic and unrealistic goals of centralism.
Kim Jong-un, the WPK and the wider structures of North Korean government presumably hope that that Seventh Party Congress will hold a more auspicious place in national history - less an attempt to address past failures than a show of strength and conviction in the face of uncertainty.
North Korea makes its ominous announcement.
Unlike the relatively concise party congresses held elsewhere, North Korea's now-rare events last a full year. Following the no doubt dramatic governmental set pieces planned for May, committees and subcommittees will inculcate and propagate the Congress decisions and agenda across the entire institutional ecosystem.
And just as 2015's events to celebrate the 70th anniversary of the 1945 liberation of the Korean Peninsula from Japanese occupation were reconfigured to last an entire year and to shape institutional agendas for the full 12 months, so the Seventh Party Congress set to begin this May will dominate Pyongyang's year. The announcement of a hydrogen bomb test, genuine or not, fits that agenda perfectly.
Beyond the Fringe
Pyongyang's test has already sent out serious geopolitical shockwaves. China's rather hostile response, combined with the recent rapprochement between Japan and South Korea, could put North Korea in a much tighter diplomatic spot than past tests have, since it is now as isolated in the region as it's ever been.
Perhaps Pyongyang is bargaining that the Obama administration will push for a peace deal of sorts on the Korean Peninsula, a follow-up to its complicated successes in Cuba and Iran. But Pyongyang may well have entirely misjudged the geopolitical mood and preoccupations with refugees or the Islamic State; neither its past "treasured swords" nor any new "forest of arms" can truly protect it or mitigate the fallout.
So the impending party congress will provide a useful stage from which the North Korean state can expound on its supposed triumphs and superiority. And if Pyongyang finds itself increasingly isolated, restrained and restricted even by former allies, it'll become a forum for all the necessary denunciations and rhetorical resistance.
So irrational and irresponsible as Pyongyang's nuclear development may seem, it is always worth remembering that North Korea has a very particular strategy in mind. As far as its leaders are concerned, nuclear weapons capability - whether based on uranium or hydrogen - is the ultimate guarantor of its national and regime security. Ultimately, Pyongyang's "treasured swords" put it at the geopolitical table in a way that most other marginal and authoritarian states (Turkmenistan, say, or Sudan) can only dream of.