North Korea has not conducted any explosive tests required to miniaturize a nuclear warhead this year, Seoul’s Defense Ministry said Thursday, indicating that Pyongyang’s technology may have gone beyond a level that requires frequent detonation experiments.

During a parliamentary audit, Cho Bo-geun, chief of the Defense Intelligence Agency under the ministry, confirmed it, triggering the speculation that the North was already well on the way to being able to mount nuclear warheads on missiles.

The North has claimed that it has already entered a technological phase to “miniaturize and diversify” its nuclear weapons.

Since 1980, the North is presumed to have conducted more than 100 high-explosive detonations as well as the three nuclear tests in 2006, 2009 and 2013, all of which have helped it gradually enhance its nuclear weapons technology.

Noting that the size of the vent of an explosion facility in the North was found to have been reduced, a Seoul official said that this could mean the need for additional tests has decreased.

“Given the change in the size of the vent and the absence of additional tests, the North might have concluded that it does not need to conduct explosion tests often, as it has already reached a considerable level of the miniaturization technology,” the official said, requesting anonymity.

During the audit, the ministry made it official that it would adopt offensive operations for border defense in the wake of a set of North Korean provocations last month including the Aug. 4 land mine detonation.

“We will carry out offensive operations in the Demilitarized Zone and establish specific operational postures based on various scenarios of possible (North Korean) provocations,” Seoul’s Defense Ministry said in its written policy report submitted during a parliamentary audit.

The statement marked a shift from the hitherto defensive operational tactics that were designed to fend off North Korean forces’ infiltrations across the border.

The shift came amid growing calls for the South Korean military to respond more proactively to North Korea’s limited attacks. The mine detonation inflicted serious injuries to the legs of two South Korean troops, followed by an artillery attack on Aug. 20.

“We will focus on formulating specific plans to prepare for various types of provocations and making them applicable through specific combat procedures,” the ministry report said. “After the North Korean provocations (last month), we also keep a cooperative mechanism with the U.S.”

As for the possibility of North Korea’s additional provocations, the ministry did not rule it out, noting that Pyongyang could launch a missile around Oct. 10, when the communist state is to celebrate the 70th anniversary of the foundation of its ruling Workers’ Party.

But there has not been any clear sign yet that the North is going to launch a rocket on Oct. 10, Seoul’s Defense Minister Han Min-koo said.

On the same issue, Foreign Minister Yun Byung-se, in a separate parliamentary audit, said that the North could launch a “strategic” provocation around the anniversary.

“Despite the Aug. 25 bilateral agreement, (we) cannot rule out the possibility that the North would launch a strategic provocation such as a long-range rocket launch, disguised as a satellite launch, around the time when they mark the anniversary of the party’s foundation,” Yun said.

“We are closely watching the situation. We will strive to forge the international opinion that would prevent the North from setting off additional provocations.”

The Foreign Ministry said in its parliamentary report that should the North launch a strategic provocation, it would “sternly and promptly” deal with it through bilateral and multilateral mechanisms including the U.N. Security Council.

Meanwhile, the Defense Ministry said that since 2010, Pyongyang had launched provocations on 64 occasions, including 13 land-based provocations and 47 cases at sea.

During the period, Pyongyang violated the Military Demarcation Line eight times and fired artillery shots across the border five times. The MDL violations, which did not occur between 2010 and 2013, began last year, the ministry noted.

North Korean patrol ships’ violations of the Northern Limit Line, a de facto maritime border, took place twice in 2010, five times in 2011, twice in 2012, nine times in 2013, 13 times last year and 10 times so far this year.

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