By Alex Jensen
SEOUL
North Korea has strengthened its border to cope with a counterattack from the south in the event of war, according to a Seoul government source Sunday -- suggesting there may be substance behind Pyongyang's aggressive rhetoric.
Previously South Korea and its ally the United States were thought to be able to annihilate North Korean artillery batteries within three minutes of a conflict breaking out.
North and South Korea have maintained an uneasy truce since 1953 -- thousands of troops still surround a demilitarized zone at their border.
The South Korean government source, cited by local news agency Yonhap, explained that "changes have been detected in the shape of the bunkers for self-propelled guns, which belong to artillery units of the North's 4th Corps in Hwanghae Province."
North Korea's decision to shift the entrances of the bunkers to face north means that South Korea and the U.S. would have to attempt to nullify the artillery batteries from the air -- risking aircraft and personnel.
South Korea's capital Seoul and its heavily-populated surrounding region is within range of the North's howitzers, which were involved in the fatal shelling of Yeonpyeong Island in 2010.
Memories of that surprise attack, along with Pyongyang's repeated war threats, have placed the South on alert.
Oct. 10 marks the anniversary of the founding of North Korea's ruling party, and the date has been identified by Seoul as a possible occasion for the military state's next provocation.
As the North continues to defy the United Nations with its unabashed development of nuclear weapons, Pyongyang has resisted calls to follow Iran's example by striking a deal in return for greater international inclusion.
