Illustration: Liu Rui/GT

Is China's sensible goal of maintaining stability in North Korea leading to unintended consequences that pose new challenges to broader stability in Northeast Asia?

North Korea's widely condemned recent nuclear and missile tests have raised tensions and unsettled the geopolitical equilibrium in Northeast Asia.

That is one way to view the unprecedented debate raging in South Korea over whether Seoul needs to acquire its own nuclear weapons. It is what international relations theorists call a "security dilemma" - when one nation's actions to increase its security result in other nations feeling less secure and taking similar measures, it will lead to spiralling tensions.

After each of Pyongyang's three nuclear tests, there have also been surges of popular support for the acquisition of nuclear weapons in South Korea, but they quickly faded. However, the combination of back-to-back nuclear and intercontinental ballistic missile (ICBM) tests, raising the specter of a new threat level, has unnerved many in South Korea more profoundly than before. A recent ASAN Institute poll found that nearly 54 percent of South Koreans - including ruling party Parliamentarians - favored acquiring their own nuclear weapons.

The proliferation of nuclear weapons has been a classic tale of the chain reaction security dilemma since the Soviet Union broke the US nuclear monopoly after WWII. China's concerns over threats to Mao Zedong's revolution led Beijing to acquire nuclear weapons in 1964. After China decisively defeated India in a 1962 border war, Delhi began its own pursuit of the ultimate deterrent. And of course Pakistan was not far behind.

There is a history of South Korean interest in nuclear weapons. After the bitter US defeat in Vietnam, many in Asia doubted the continued US commitment to the region. Then former South Korean president, Park Chung-hee (the current president Park Geun-hye's father), launched a secret effort to build nuclear capabilities in the late 1970s. But Washington discovered the fledgling nuclear program and persuaded Park nuclear weapons would not enhance security and that maintaining the US-South Korea alliance was a better choice.

The US nuclear umbrella, extended through its long-standing alliances with South China and Japan, has underpinned stability. But as North Korea moves toward attaining the capability of a nuclear-tipped ICBM that could reach the US, doubts about US extended deterrence have festered across the Asia-Pacific.

These emerging strategic realities have led Japan to make large investments in ballistic missile defenses. Now Seoul is also in talks with Washington about acquiring a THAAD missile defense system which would integrate into the US-Japan defense network.

Beijing argues that citing North Korea is just an excuse for the US to put in place a missile defense system aimed just as much at containing China. Whether that is true or not, it is difficult to tell South Koreans, alarmed at Pyongyang's belligerence, that a North Korea armed with nuclear weapons is not a legitimate threat.

Park has sought to build a strategic partnership with China, and Chinese relations are a strategic priority for Seoul. But many South Koreans have been disappointed at Beijing's heavy pressure on Seoul not to pursue missile defenses, and whether fair or not, have the impression that China seems more upset at Seoul's interest in THAAD than at the outrageous behavior of its defiant ally North Korea.

As host of the now stalled Six-Party Talks on denuclearization, China has led cooperative efforts with South Korea, the US, Russia and Japan. Beijing has supported four UN Security Council resolutions placing sanctions on Pyongyang for its nuclear and missile tests. But now that admirable track record of ongoing cooperation among the major powers in Northeast Asia is at risk.

It does not take much imagination to envision the possible chain of events that would follow if Seoul went nuclear. Would Japan be far behind? How about Taiwan which tried twice in the past, but was blocked by the US? But despite lingering doubts, all prefer US security assurances to the uncertainty of living without them. The Park government rejects the nuclear option.

 The challenge to Seoul, Washington and Beijing is to find new ways to effectively counter and reverse North Korea's nuclear ambitions. The new UN Security Council resolutions with tougher sanctions against North Korea are a good first step. But lowering tensions and enhancing stability in Northeast Asia will require bold and creative measures.

The author is a senior fellow at the Atlantic Council. He served as a member of the US Department of State Policy Planning Staff from 2004-08, and on the National Intelligence Council from 2008-12. opinion@globaltimes.com.cn. Follow him on Twitter @Rmanning4.