SEOUL, South Korea —
"That would make it hard for us to bring in materials and ship out new products," said the worker, who wouldn't provide his name because of company rules.
The worker, who has been in Kaesong since Monday, said he wasn't scared.
"It's all right. I've worked and lived with tension here for eight years now. I'm used to it," he said.
Since 2004, the Kaesong factories have operated with South Korean money and know-how, with North Korean factory workers managed by South Koreans. The factories provide jobs and bring in much-needed hard currency for North Korea, and supply a cheap and efficient labor source for South Korea.
Other examples of joint inter-Korean cooperation that blossomed during an earlier era of detente came and went during the previous administration of South Korean President Lee Myung-bak, whose tough policies on North Korea angered the Pyongyang regime.
North Korea also cut the Kaesong line in 2009, in a protest of that year's South Korean-U.S. military drills. North Korea refused several times to let South Korean workers return home from their jobs, leaving hundreds stranded in North Korea. The country restored the hotline and reopened the border crossing more than a week later, after the drills ended.
North Korea's actions have been accompanied by threatening rhetoric, including a vow to launch a nuclear strike against the United States and a repeat of its nearly two-decade-old threat to reduce Seoul to a "sea of fire." However, analysts outside the country have seen no proof that the country has mastered the technology needed to build a nuclear warhead small enough to mount on a missile.
In a sign of heightened anxiety, Seoul briefly bolstered its anti-infiltration defense posture after a South Korean border guard hurled a hand grenade and opened fire at a moving object early Wednesday. South Korean troops later searched the area but found no signs of infiltration, and officials believe the guard may have seen a wild animal, according to Seoul's Defense Ministry.