With North Korea repeatedly warning of “nuclear retaliatory strikes,” questions have been raised over whether Pyongyang’s threats are credible or simply for deterrence and to up the political ante.

Experts largely agreed that although its nuclear arms posed a formidable threat, the communist state was unlikely to consider a preemptive nuclear attack inviting an overwhelming retaliation that would doom the dictatorial regime.

But some noted that fledgling leader Kim Jong-un, struggling to project an image of a charismatic leader for the 1.19-million-strong military, could think irrationally and make misjudgments leading to a catastrophic decision.

“Even if (the North) might have a policy of ‘no first use,’ the efficacy of the nuclear arms is political impact. With the threat of nuclear arms, the North could frighten the South and occupy it without using conventional arms,” said Lee Choon-kun, a security expert at the Korea Economic Research Institute.

“This is why all countries under the threat of nuclear attack possess nuclear arms. Of course, that excludes South Korea.”

North Korea conducted three atomic tests in 2006, 2009 and last month, and vowed to “make permanent its status as a nuclear power.” It has constantly enhanced its delivery technology, threatening the security of the U.S. and its allies.

Weeks before South Korea and the U.S. launched its annual 11-day Key Resolve exercise on Monday, Pyongyang ratcheted up its bellicose rhetoric, calling the drills a “rehearsal for a nuclear war of incursion.” As the level of its threats increases, Seoul said the North was employing “psychological tactics” to frighten South Koreans.

Pyongyang appears to be seeking to secure the so-called “first strike capability” ― a preemptive surprise nuclear attack capability to defeat another nuclear power. But it seems to have a long way to go to reach that when the U.S. provides a nuclear umbrella to its key Asian ally South Korea.

“North Korea may be able to launch a ‘first strike’ with nuclear weapons against South Korea, Japan, or China. But a ‘first strike capability’ usually refers to a country being able to use nuclear weapons to destroy all or most of an opponent’s nuclear weapons capability ― preventing an opponent’s retaliation,” Bruce Bennett, a senior defense analyst at the RAND Corporation, told The Korea Herald by email.

“North Korea has no such capability ― it cannot destroy the U.S. nuclear weapon forces to prevent a U.S. retaliation.”

Kwon Tae-young, adviser to the non-profit Korea Research Institute for Strategy, echoed Bennett’s view, underscoring that Pyongyang was simply “blowing things way out of proportion” with its unproven, unreliable nuclear capability.

“North Korea may have some 10 nuclear warheads that could be operational, but it does not have reliable delivery vehicles yet except for aircraft, which could be easily shot down. It has yet to reach the sufficient level of the payload miniaturization,” he said.

“Washington provides extended deterrence to South Korea. How can we compare the U.S. capability with North Korea’s although under the new Strategic Arms Reduction Treaty with Russia, the U.S. aims to reduce its warheads? The North is just bluffing too much.”

Under the new START between the U.S. and Russia, the two powers limit each side to 1,550 strategic nuclear warheads, down from 2,200.

Along with the first strike discourse, whether Pyongyang has been developing a second-strike capability is also a critical question in gauging the reclusive state’s nuclear strategy.

The second-strike capability is a country’s assured ability to launch an overwhelming nuclear retaliation after suffering an attack. This forms the basis of a condition referred to as “mutual assured destruction” that maintained the “balance of terror” during the Cold War era. Submarine-launched ballistic missiles are part of the method for the capability.

Experts largely agreed that the North’s nuclear technology was nowhere close to second strike capability. But its mobile launch systems could pose challenges to deterring a provocative North Korea, they pointed out.

“North Korea’s nukes are ground-based. They could be carried by mobile launchers or hidden into caves or underground tunnels, which make it difficult to detect their movements,” said Kwon.

“But whether it has developed such easy-to-hide or mobile platforms is still unknown. And it takes considerable technology, and Pyongyang may need much more time to secure that. It does not appear to have completed warhead miniaturization.”

Bennett was also skeptical about Pyongyang’s second nuclear capability.

“North Korea may have a ‘second strike capability,’ meaning the ability to cause unacceptable damage to the Republic of Korea, Japan, and/or China after suffering a counterforce attack,” he said.

“But this is an issue of what would be unacceptable to these countries. For example, if North Korea could deliver one nuclear weapon against a ROK city, would that be unacceptable damage to the ROK?”

Bennett stressed that to deter the North, Seoul and Washington must make it clear that use of a nuclear weapon would be the “end of the regime,” regardless of the price the regime might impose.

“North Korea tends to ignore vague threats; the U.S. and the ROK need to be specific about the consequences of North Korea using nuclear weapons,” he said.

He also advised the allies to map out a clear nuclear deterrence concept.

“It took the better part of a decade during the Cold War for the US strategy to develop and mature; a similar process needs to proceed for what several authors now call the 2nd Nuclear Age, when small, sometimes desperate countries like North Korea pose a different nuclear threat in both quantity and quality,” he said.

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