Ahn Young-Joon / AP
South Korean vehicles return from a joint industrial complex in the North Korean city of Kaesong at the customs, immigration and quarantine office, near the Demilitarized Zone (DMZ) north of Seoul, South Korea, on Thursday.
SEOUL – On Thursday morning 530 South Korean men and women went to work as usual, much to the relief of security officials in Seoul.
But theirs was no ordinary commute to the office, as it involved crossing the heavily fortified de-militarized zone separating the two Koreas in order to reach their desks at the Kaesong Industrial Zone.
The area, which opened in 2004, is home to 124 South Korean companies who directly employ 53,000 North Korean workers. As many as 250,000 other Northerners depend on the complex, which reportedly generates up to $2 billion a year in trade, and is by some estimates the biggest source of foreign currency for Pyongyang.
The complex over the years has mostly ridden out the ups and downs of relations on the peninsula, but on Wednesday Pyongyang cut a telephone hotline responsible for guaranteeing the safety of the South Korean workers commuting to work.
The workers headed to the office Thursday anyway – after receiving assurances that things were business as usual from the complex management.
Yonhap via Reuters
A U.S. Air Force B-2 Spirit stealth bomber flies over Pyeongtaek, south of Seoul, South Korea on Thursday.
For South Korean analysts and security officials, the daily commute and the fate of the Kaesong complex has become a litmus test of just how seriously to take the barrage of bellicose threats from the North. To close Kaesong would be a major blow to the North's finances.
Tension has grown so high that two American B-2 Spirit stealth bombers practiced an attack on the Korean Peninsula Thursday as part of a joint military exercise with South Korea, dropping dummy munitions on an island range.
The move sparked more angry words from Pyongyang, which has already threatened strikes on New York, Washington and Seoul recently.
North Korea said it was cutting the last channel of communications with the South on Wednesday because war could break out at "any moment." Pyongyang also said earlier this month that it considers the armistice that ended the Korean War in 1953 void.
U.S. Defense Secretary Chuck Hagel weighed in on the tension Thursday, saying that the belligerent tone by North Korea has “ratcheted up the danger.”
‘Like an angry dog’
Despite everything, South Koreans for the most part have a remarkable ability to shrug off threats from the North.
"It's like an angry dog barking from the other side of the fence," is the way one young Korean, who asked not to be identified, described it. "Me and my friends we really don't think about it that much."
But she conceded that her grandparents, who lived through the Korean War, have a family contingency plan.
"They tell us that if there's chaos in Seoul, we should all aim to meet at the central station every Wednesday at 4 o'clock."
Another young women, an employee of one of Korea's big consumer electronics companies who also spoke on the condition of anonymity, said that of late she'd been receiving more calls from friends in the States asking whether she's okay.
"'Relax,' I tell them. ‘We're used to this.’"
Domestic politics or blackmail?
Still, the intensity and regularity of the threats is worrying to many analysts here. Some here caricature Kim Jong Un as a as a kind of bad James Bond villain, so over-the-top that he can't possibly be taken seriously. Others worry that he is young and untested, and is now faced in the South with a new president, Park Geun-hye, also untested, but promising a more robust approach to any skirmish with the North.
U.S. Secretary of Defense Chuck Hagel and General Martin Dempsey discuss the escalating tensions on the Korean Peninsula and the recent training missions conducted by U.S. stealth bombers.
She's threatened to hit back hard if there's a repeat of the 2010 attacks on a South Korean island or patrol boat in the tense west sea region, which analysts see as the most likely flashpoint.
Analysts broadly fall into two camps: the "it’s all about domestic politics" group and the "blackmail" group. The former sees the rhetoric as aimed primarily at a North Korean domestic audience, and reflecting the young Kim's insecurity, whipping up support at home by generating paranoia and hysteria.
The latter group thinks Kim is genuinely angry at new sanctions and military exercises between the U.S. and the South. They say the rhetoric is all about money, aid and resources, and more broad recognition as a nuclear state and direct talks with the U.S.
Meanwhile life goes on in Seoul, the most wired city on the planet. This vibrant metropolis of more than 10 million people has more and faster broadband connections than anywhere else on the planet, but sits just 30 miles from the world's most fortified border.
You only need travel a few miles north of here to encounter the first watchtowers and razor wire lining the banks of the Han river.
But you'd never know it amid the buzz of downtown Seoul. Or from the editorials in Thursday's Korean Herald, which were sinking their teeth into the nomination of the Fair Trade Commission and the challenges facing the National Tax Office.
The South Korean defense ministry has reassured people that it hasn't detected any unusual military movements across the border. Others question the North's ability to deliver on some of its more blood-curdling threats.
But the dog continues to bark.
And savvy analysts are focusing ever more closely on that daily commute to Kaesong.
The Associated Press contributed to this story.