The timing of North Korea’s latest nuclear test is smarter than it looks

North Korea's Kim Jong Un, shown in an image released by North Korea's state-run KRT television service on September 9, 2016. North Korea conducted its fifth nuclear test on the same day. KRT

What made North Korea decide to conduct its fifth nuclear test last Friday? No doubt because Pyongyang believed that China would allow Kim Jong Un to get away with it. Again.

After Pyongyang's fourth nuclear test in January, the UN Security Council signed off on the UN's toughest sanctions against North Korea to date. Beijing, a permanent council member long frustrated by its neighbor, seemed to have signed off on a package of tough measures indeed.

Those sanctions included bans on key North Korean exports, though with a vaguely worded exception for "livelihood purposes." The measures specifically targeted extractives like coal and iron ore, which North Korea leans on heavily for revenues. They also greatly restricted options for international banking by North Korean institutions.

However, China's fundamental position regarding the Korean peninsula remained the same: no war, no instability, no nukes. The sequence of that oft-repeated maxim is no accident. Those are the conditions Beijing seeks to avoid, in that order. Nuclear weapons are a distant third place in that range of apprehensions.

Following the Koreas, of course, China would bear the brunt of war or instability on the peninsula, in the form of refugees and severe economic pain. As much as it frustrates Beijing, Chinese leaders continue to believe that nuclear North Korea is a problem that can and should be managed through diplomacy. Since its third nuclear test in 2013, China has been more comfortable with economic pressure as part of the policy mix regarding North Korea (officially the Democratic People's Republic of Korea, or DPRK), but it is still unwilling to push Pyongyang to the point of destabilization.

As such, Beijing—virtually Pyongyang's only trading partner—has implemented some of the measures specified, but seems to be frequently exercising that significant loophole regarding coal. Chinese imports of North Korean coal fell sharply in April and May after sanctions were announced, but rebounded strongly by June.

In Pyongyang, policymakers will have been paying keen attention to Beijing's public statements, information gleaned from backchannel communications with Chinese officials and facts on the ground for its businesspeople in China since March. They have sensed that they can cope with the "new normal" imposed on North Korea by the updated sanctions environment. They have judged that China's fundamental position has not changed, providing leeway to conduct another test.

Indeed, Beijing immediately called for a return to talks in the wake of the nuclear test, but Washington and Pyongyang aren't even close to finding a mutually acceptable starting position. The Obama administration has lowered the bar to its minimally acceptable height. Secretary of State John Kerry said it most simply last week in Geneva: "All Kim Jong-un needs to do is say, 'I'm prepared to talk about denuclearization.'"

Expert opinion is somewhat divided as to whether or not the DPRK does someday want to discuss some sort of denuclearization in the near future. It's likely that someday it will, but for now sees the possession of a credible threat against the U.S. mainland as irreplaceably advantageous. From Kim Jong Un's perspective, why not bargain from a position of strength?

Pyongyang chose to conduct the test on its national independence day, but that doesn't truly answer the question: Why now?

Why, for example, didn't Pyongyang wait to conduct a test closer to the U.S. election? An information-saturated electorate will have largely forgotten this test by the time they head to the polls in November, but exploding a device in late October would have provided Donald Trump with fresh ammunition to attack the Obama/Hillary Clinton foreign policy strategy of strategic patience. Trump is Pyongyang's preferred candidate as he introduces a degree of unpredictability, given his disregard for diplomatic convention and apparent lack of knowledge about the Far East.

Or why not let the sharp deterioration in China-South Korea relations play out a little longer? Seoul responded to North Korea's January nuclear test by allowing the United States to deploy its Terminal High Altitude Area Defense (THAAD) in South Korea. THAAD essentially detects and shoots down ballistic missiles. It has been controversial in South Korea in large part because China has been so vociferously against it: Beijing views it as targeting the People's Liberation Army as part of a U.S. strategy to contain China.

Due to THAAD, China-South Korea relations have gone from stellar to strained in a few short months. Last year, President Park Geun-hye was the only U.S. ally to attend Beijing's celebrations marking the 70th anniversary of the end of World War II. This year, South Koreans are concerned about some form of economic retaliation over THAAD by Beijing. Events between China and South Korea have been canceled, there are rumors of visa-issuance problems, and Beijing has already been looking to reduce the influence of South Korean pop culture.

It may be that Pyongyang saw the acrimony between Seoul and Beijing and judged that these divisions would hamper cooperation against it if it conducted its fifth test now. But why not wait a little longer and see if Beijing's rhetoric on THAAD turned to stronger reprisals? This could in turn provoke an anti-China backlash in South Korea and help create a powerful negative cycle between two famously nationalistic citizenries. By testing now, Pyongyang runs the risk of muting what could become serious discord between it two neighbours.

That said, an editorial in the Chinese state-run Global Times on the day of the fifth test seemed very much to equate the sins of nuclear development and THAAD, putting them at the same level. If that really reflects the Chinese government's position, then perhaps Pyongyang has judged correctly and now is as good a time as any.

The fact is, due to the DPRK's opacity, we struggle to know exactly why they conducted their 5th nuclear test at this moment. We do, however, have a clearer idea of their long-term strategy under Kim Jong Un: to have (or come close to) a miniaturized nuclear weapon and a missile that it can deliver to the U.S. mainland.

Andray Abrahamian is an Honorary Fellow at Macquarie University, Sydney and a contributor at 38north.org and Reuters.