In a season of repeated North Korean provocative steps, the 3 September underground nuclear test ranks as the most serious to date. Not only will it significantly inflame regional and international tensions, but it also is inherently dangerous. The test, which was felt across swathes of Jilin province, China, about 100km away, inevitably presents the risk of radioactive gas venting from the subterranean test site, with potentially horrific consequences for the health and livelihoods of local people.

Objectionable and perilous as it might be, this development – like the series of missile tests that Pyongyang conducted in recent months – essentially amounts to another reminder that the North Korean government is determined to push forward with its military nuclear and missile programs. This, the sixth such nuclear test since 2006, proves North Korea’s capacity to build devices many times more powerful than those used by the U.S. against Japan in 1945. Pyongyang aims to demonstrate its nuclear deterrent capability to the world once and for all, prior to the 70th anniversary of its founding in September 2018. It won’t be stopped by the short-run costs of its actions in terms of international isolation, U.S. threats, or sanctions.  

But although there is reason to worry, there is no reason to panic. One critical step to reduce the risk of military conflict would be for the U.S. and South Korea to better coordinate their efforts on behalf of the security of South Korea and its people. South Korea is perennially tempted, particularly under liberal presidents, to see its military alliance with the U.S. as a major obstacle to better relations with the North and thus to believe that downgrading or reconsidering it could be a possible solution. This reading, though it may once have been true, ignores decades of history between the Koreas. For its part, the current U.S. administration says it is uncertain about the utility of stationing troops abroad. But weakening this alliance risks emboldening North Korea. It is essential to hold the line.

At the same time, it is imperative that Washington, Seoul, Beijing and all other stakeholders redouble their efforts to craft a common diplomatic approach. The unanimous passage of another UN Security Council resolution would be welcome, but – as evidenced by Pyongyang’s response to the last such step – clearly insufficient. A more coherent, united diplomatic approach is needed to complement steps to deter North Korea, given the apparent inability of outsiders to force Pyongyang to step back from its goal of militarising its nuclear capacity. In this respect, some of President Trump’s latest intimations or pronouncements – suggesting that South Korea is flirting with appeasement; contemplating an exit from the South Korea trade deal; or toying with the prospect of a preventive war – are self-inflicted wounds. Instead, the focus ought to be on unified deterrence and diplomacy, in particular reaching agreement on the principle of initiating talks with Pyongyang, even at the price of controversial concessions such as removing any precondition or barrier to negotiations. There is no other viable way forward.

And it may conceivably be a way to which Pyongyang ultimately accedes. Indeed, its triumphalist tone notwithstanding, domestic reporting from North Korea suggests the regime also wanted to convey the message that it is a responsible actor, that its nuclear program is secure, and that it is aimed solely at credibly deterring U.S. aggression. State media led with a report on a meeting of the country’s politburo standing committee convened on the morning of the test, during which international circumstances and peninsula tensions were debated by leaders of party, state and military. Only then did they report on the successful nuclear test itself. Such subtleties will be of cold comfort to those for whom North Korea looms as their greatest threat. But it might be read as North Korea’s very indirect invitation to start talks.

If that is the case, of course, there would be ways for North Korea to more clearly signal its intent. If the latest test really truly involved a thermonuclear weapon capable of being mounted, then Pyongyang has achieved its technical goal. It could seize the opportunity to declare an immediate moratorium on further testing. In that context, it also could work with the Chinese government to ensure that the 3 September test has not negatively impacted the environment of the Yanbian region just across their shared border. Finally, it could offer to cooperate with the Republic of Korea on the long overdue task of reestablishing a military hotline between the two countries. These are all minimum steps North Korea would take if it wished to reassure the world that it does not intend the current crisis to get any worse. They also are unlikely, at least in the short term, which is why the burden almost certainly will fall on outside actors – the U.S., South Korea and China prime among them – to forge a coherent approach combining deterrence with diplomacy. And why they will need to avoid needless divisions and discordant messages that undermine their effectiveness, send mixed messages and thus heighten the very risks they have every interest in lessening.