SEOUL, April 3 (Yonhap) -- North Korea's decision to bar entry of South Korean workers and cargo to the Kaesong Industrial Complex is seen as a move to ratchet up tensions on the peninsula as the communist country has vowed to strike back at any attempt to challenge its sovereignty by outside forces, observers here said Wednesday.
Observers said the latest move poses the most serious challenge to the operation of the complex since it started churning out products in late 2004. The action also comes a day after Pyongyang said it will move to restart the operation of its 5 megawatt graphite moderated reactor in Yongbyon that had been mothballed following an agreement reached at the six-party talks in 2007. Such a step could render the country capable of reprocessing spent fuel rods and extracting plutonium.
The North also said over the weekend that it could close the Kaesong Industrial Park completely -- home to 123 South Korean companies -- if Seoul and Washington continue to provoke it with military drills and threats of imposing sanctions.
Related to the action taken by the North, Unification Ministry spokesman Kim Hyung-suk said in a press conference that while the North temporarily barred passage of workers and cargo in 2009 during that year's annual Key Resolve exercises, the latest move should be viewed as a serious development.
He stressed that Seoul views the latest actions as being extremely regrettable and called on the North to lift the ban immediately.
However, Lim Eul-chul, a research professor at Kyungnam University, predicted it is not likely that the North will close down the complex completely because it has grown in size and has a significant impact on the North Korean economy. Some 53,000 North Korean workers are employed at the factory and it is a source of income for the impoverished country.
He said the latest actions can be seen as a way for Pyongyang to show its displeasure toward the ongoing Foal Eagle military drill and the sanctions being imposed by the international community after the isolated country detonated it third nuclear device on Feb. 12.
The expert added that the restriction could be seen in same light as recent threats, like Pyongyang's announcement that it will no longer abide by the Armistice Agreement that halted the Korean War (1950-53) and not respect non-aggression pacts signed with the south in the past.
The country that conducted three nuclear tests and launched a long-range rocket that could reach the United States recently warned it could launch pre-emptive nuclear attacks against its foes and turn Seoul and Washington into a "sea of fire."
Others said that Pyongyang may have taken the action because the United States, China, Russia and South Korea all joined forces in attacking its announcement to reopen the Yongbyon reactor and related facilities.
Besides the 5 megawatt reactor, the Yongbyon site is home to larger reactors, a nuclear reprocessing facility and a fuel rod manufacturing plant.
Experts said that depending on developments, the North can opt to further fuel tensions.
Chang Yong-seok, senior researcher at the Institute for Peace and Unification Studies at Seoul National University said that from a broader perspective, all actions taken by the North are an attempt to raise tensions to a fevered pitch so as to compel Washington to come to the negotiating table.
"Pyongyang may be upping the ante so as to change the ceasefire armistice pact into a permanent peace treaty," the scholar said. In order for the North to reach its objective, it may be willing to take losses that could come if Kaesong is closed, he said.
Even though the North placed no restrictions on South Korean nationals leaving the country, the researcher warned that there is even the risk that the country may move to further escalate tension by preventing the workers from leaving temporarily, which could raise alarm bells. The Seoul government has said that the safety of workers is their paramount concern, with the military hinting it may even implement a rescue plan if the North opts to hold workers hostage.
In addition, political observers said the North's latest actions may be aimed at triggering internal discord within South Korea. Already the representatives of businesses at Kaesong urged the Park Geun-hye administration to kick start the Korean Peninsula peace process that the president pledged during last year's election campaign. They urged local media not to release articles that hurt North Korea's pride and could lead to actions which directly impact business interests.
Meanwhile, the North has further escalated tensions by its leader Kim Jong-un ordering the country's rocket forces to be ready to take immediate action if the order is given, and also told the country's field artillery units to be on standby.
The new leader, who took control over the country after the death of his father in late 2011, has made numerous visits to military bases this year and personally guided military drills.