The U.S. and China are expected to recalibrate their approaches toward North Korea and seek more effective denuclearization measures following its third nuclear test on Tuesday, experts said Wednesday.

But the two powers apparently face policy dilemmas over Pyongyang.

Severe punishment could bring it to the brink of a collapse that could destabilize the region, but tougher sanctions for the provocation are inevitable, they said.

China, the major ally and patron of the impoverished state, could start rethinking the strategic value of the North given that it has continued to be a source of regional instability that could hamper Beijing’s efforts to focus on domestic issues such as income disparities and a slowing economy, experts said.

“Regional security conditions following the nuclear test are not favorable to Chinese interests. Japan could take advantage of it to spur its efforts to become a normal state with a full-fledged military,” said Kim Heung-kyu, a politics and diplomacy professor at Sungshin Women’s University.

“The nuclear threat could also lead to the strengthening of security cooperation among South Korea, Japan and the U.S., which China fears could be used to keep it in check. It would also raise instability and uncertainty in the region, which is not strategically palatable for Beijing.”

But Kim stressed China is unlikely to seek any fundamental change in its policy line toward its communist ally. After the atomic test, Beijing’s Foreign Ministry called for “calm and restraint,” hinting at its opposition to too harsh punishments against the North.

“North Korea still remains strategically crucial as the rivalry between the U.S. and China intensifies and the level of confidence in South Korea-China relations is still low,” he said.

“Under these circumstances, there is no critical motive from China’s perspective to apply too strong sanctions that could put the North Korean regime in a difficult position. Beijing would stick to its principles of peninsular stability and denuclearization, but agree to additional sanctions that could send a warning message to the North.”

Kim added that China’s unprecedented last-ditch efforts to dissuade the North from the test were notable as they signaled that China’s strategic thinking had grown out of the past Sino-centric ideological frame and started to consider normal inter-state relations.

Suh Jin-young, professor emeritus at Korea University, echoed Kim’s view that China could seek tougher denuclearization measures, but might not make any major policy shift.

“A sure, effective measure to denuclearize the North may be a military strike, but no one, including China and the U.S., can come forward to do that. Then what China can do is to apply sanctions in the economic realm over which it has the strongest influence,” said Suh.

“But the degree of the North’s reliance on foreign trade is very low, and China would not agree to severe economic sanctions that could bring it to the cusp of collapse as possible instability in the North sharing the border with it could undermine China’s national interest.”

Already under severe isolation caused by its missile and nuclear tests that violated U.N. resolutions, Pyongyang is known to receive from China some 300,000-400,000 tons of grain and 500,000 tons of oil each year. The North’s annual food shortage amounts to around 800,000 tons while its annual oil consumption is around 1 million tons.

Some observers predicted that China would slowly realize the North might not be a strategic asset for its future, and could seek a change of the regime in a way that best serves its national interest.

“Amid the intensifying contest between the two major powers, China would need the North as a strategic buffer zone. But as the Kim Jong-un regime committed the (provocation) that went beyond China’s control, Beijing could consider a regime change as part of its mid- and long-term strategy,” said Huh Moon-young, a senior fellow at the state-run Korea Institute for National Unification.

“Beijing knew who Pyongyang was and how it would move regarding the nuclear test, and Pyongyang also, already, knew how Beijing would react to it. The nuclear test sort of revealed the true reality of their (shaky) relationship.”

Like China, North Korea’s nuclear issue remains a serious foreign policy challenge for the U.S., particularly at a time when Washington struggles with domestic financial constraints, a volatile Middle East, spreading terrorism in Africa and Iran’s nuclear threat, not to mention the intensifying Sino-U.S. rivalry.

“North Korea used to remain near the bottom of the U.S. foreign policy agenda, but the nuclear test brought it to the very top,” said Choi Kang, a professor at the Korea National Diplomatic Academy.

“The U.S. might step up its pressure on the North through U.N. sanctions and is unlikely to seek any approach that might appease Pyongyang for its denuclearization, for the time being.”

In addition to its development of miniaturized nuclear warheads, the North’s successful launch in December of a rocket, which experts said had a potential range of 10,000 km, ratcheted up the security threat to the U.S.

In his State of the Union speech on Tuesday, Obama vowed to stand by the allies in the region, strengthen missile defenses and lead the world in taking “firm action” in response to the North’s threat.

Chuck Hagel, President Barack Obama’s Pentagon chief nominee, said during a Senate confirmation hearing that the North is a “real nuclear power and quite unpredictable.” Obama called the nuclear test a “highly provocative act.”

Nam Chang-hee, political science professor at Inha University, said that the U.S. would step up trilateral security cooperation with South Korea and Japan, and would call on China to join tougher anti-Pyongyang sanctions.

“After the atomic test, the environment for the U.S. to seek direct talks with the North has become far more difficult. It will seek how Seoul would react to the case and seek stepped-up cooperation with its allies of the South and Japan,” he said.

For Japan, its conservative political circles could take advantage of the North Korean nuclear challenge to strengthen its rationale for military rearmament.

“Chances are high that Japan could politically use the North Korea factor to spur its rightward shift. It could say that because of the North, it should have a full-fledged military and should be rearmed,” said Lee Jung-hwan, assistant professor at the School of International and Area Studies of Kookmin University.

But Lee said for the short term, the new Shinzo Abe government would focus on economic issues as his Liberal Democratic Party sought to clinch a powerful majority in the upper-house parliamentary elections slated for July.

“Still, domestically, the key issues are economics. Given this, for the short term, Tokyo might seek to focus on revitalizing the economy for the domestic sentiment.”

By Song Sang-ho (sshluck@heraldcorp.com)