SEOUL ― Repeating the past, North Korea’s young ruler Kim Jong-un has threatened the U.S. and South Korea with dire consequences for opposition to the nation’s missile adventurism. In a break from the past, Kim issued thinly disguised criticism of North Korea’s principal benefactors ― China and Russia. The latest turn in North Korea’s brinkmanship will test China’s newly installed party Secretary General Xi Jinping.

In strident responses to U.N. Security Council’s Jan. 24 resolution stiffening sanctions over the December rocket launch, the North claims it’s ending talks over denuclearization efforts; it will also conduct a new underground nuclear test of a “high level” device, predicted to target the United States.

The threat against the U.S., the first since Kim’s inauguration, followed signs of a thaw. Its most striking element was Kim’s veiled criticism of “some big nations” for failing to create what it called “fair and just international order,” allowing small countries like North Korea to develop nuclear arsenals. North Korea was clearly stung by Resolution 2087, unanimously supported by all 15 nations, including China and Russia, with calls for tightening control over the North’s international financial transactions and freezing assets of six organizations including its space agency. The resolution adds four individuals to travel bans and promises promises further “significant action” if the North continues violating sanctions.

Before the recent crisis, Kim seemed to offer an olive branch to South Korea. Kim, 30, departed from tradition and in the first radio speech by a North Korean leader since 1994, he suggested: “An important issue in putting an end to the division of the country and achieving reunification is to remove confrontation between the North and South.” Some analysts speculated that he might be ready for dialogue with the new government of South Korea’s President-elect Park Geun-hye.

His volte face in threatening South Korea for supporting the U.S. thus has raised speculation. Few can fathom the mood in Pyongyang and and a regime operating in opacity: Is an omnipotent military group pressuring Kim? Is he panicking at the prospect of tighter U.N. sanctions?

With the North Korean military system deeply involved in weapons trade, especially nuclear and missile technology with Iran, it’s possible such factors are at play. The North’s statement indicates Kim is stung by China and Russia’s support for the resolution, although China agreed to back the U.S. draft only on condition that no new sanctions are imposed. Thus, the draft expanded existing sanctions.

The statement suggests bitterness at a betrayal by Beijing and Moscow, Cold War allies. But such protest has its limits: State-of-the-art weaponry comes from Moscow, and the North is critically dependent on China which supplies half its food and energy ― up to 400,000 tons of grant-type food aid each year, depending on need, and 500,000 tons of crude oil, according the newspaper Chosun Ilbo. In 2003, China briefly stopped oil supply to the North after the U.S. complained about the North’s clandestine uranium-enrichment program, suggesting that China can exert control.

Beijing has leverage over the Pyongyang regime.

Why then bite the hand that feeds? Perhaps because Kim is acutely aware of the geopolitical value of North Korea as a buffer state next to U.S. ally South Korea. Kim’s latest show of defiance may also be his reaction to China’s recent courting of South Korea in the midst of growing tensions with Japan over the Senkaku territorial disputes. In a change of style in recent weeks, Xi and other senior Chinese leaders like Dai Bingguo have gone out of their way to increase contacts with Seoul officials, stressing a common stand against Japan based on history.

Asked at a Jan. 23 foreign ministry briefing how Beijing would respond to a third nuclear test by the North, spokesman Hong Lei described the situation as “complicated and sensitive” and urged restraint: “We have unfailingly advocated denuclearization of the Korean peninsula… It is China’s position that the six-party conference is the effective way to attain this objective.”

In truth, neither the policy of restraint nor the six-party talks chaired by Beijing off and on over the past decade has produced a breakthrough. The North repeatedly accepts aid, then backs off from obligations. Almost word for word, Hong contradicted the North’s stated position on the nuclear issue. The gap between what he said and China’s persistent refusal to use its leverage for taming the North’s nuclear ambitions has raised questions over Beijing’s assertion and global influence.

The foreign ministry statement is the only indication of Kim’s reaction to China’s U.N. vote. One can assume that the North would not make that challenge if it weren’t ready to stand up to Beijing. Kim exploits his geopolitical worth just as his grandfather played China against the USSR during the Sino-Soviet ideological conflict. Mao entered the Korean War as a way of stopping MacArthur’s advances into China. Beijing may oppose the North’s nuclearization, but would not contribute to ending the Pyongyang regime, thus sharing borders with South Korea.

While China’s credibility runs low in Seoul, President-elect Park has no alternative but to try using the China window to cope with each nuclear crisis. China as a Security Council member unhesitantly uses veto power on behalf of North Korea. Besides being the North’s largest source of food and energy aid, China is also Seoul’s biggest export market for Seoul. “China has a crucial role to play in making North Korea a responsible member of the international community,” Park pleaded to a Chinese envoy last week. In Beijing, receiving Park’s special emissary within hours of the North’s blistering threats, China’s Xi offered blandly: “It is the consistent position of China that denuclearization and prevention of the spread of weapons of mass destruction is essential for the peace and stability of the Korean peninsula.”

Park’s policy is to keep the door open for dialogue and providing emergency humanitarian aid when necessary. While pushing for gradual opening of dialogue, Park issued a stern warning that her government will firmly respond to additional military provocations, such as the North’s 2010 sinking of a South Korean navy vessel that killed 50 sailors. “There must be assured consequences for actions that breaches the peace,” she wrote for Foreign Affairs in September/October 2011.

That stick-and-carrot approach is welcomed by the Obama administration. A smooth Seoul-Washington security consultation could see turbulence if Senator John Kerry, nominated as U.S. secretary of state, advocates direct talks between the U.S. and the North ― especially if Seoul is left out of the bilateral process. If confirmed, Kerry is expected to review options.

If the North proceeds with testing another device, possibly with enriched uranium, as analysts speculate, this would be another wakeup call for Seoul, Tokyo and Washington. Such a test would lead the U.S. to seek stronger cooperation from China in confronting the North’s threat.

More than the U.S., China could find such a bomb to be a game changer, forcing it to reconsider its benign stance.

By Shim Jae Hoon

Shim Jae Hoon in a Seoul-based journalist. The article is reprinted with permission from YaleGlobal Online (yaleglobal.yale.edu). ― Ed.