NORTH KOREA’S porous 880-mile border with China is its lifeline to the outside world. About 39 percent of its trade last year was with China, which, critically, supplies it with 80 to 90 percent of its oil. Trafficking in money transfers and human beings also flourishes.
By contrast, North Korea’s border with Russia is 11 miles and heavily guarded; the 150-mile-long demilitarized zone with South Korea has hundreds of thousands of soldiers on each side. Until now, the North’s ships have regularly visited Japan, from which relatives sent cash and goods, but North Korea’s nuclear test is expected to end that trade.
For China, the bottom line is to erect the right number of fences, as it did along the border city of Dandong recently. Build too few and you invite instability in China. Build too many and North Korea collapses.
A collapse is clearly something Beijing doesn’t want, and why it is lukewarm toward harsh sanctions. A collapse might send more North Koreans into China than the 100,000 to 300,000 estimated to have flooded the border during the North’s great famine in the mid- to late-1990’s. (Paradoxically, the famine also opened trade links when local North Korean groups formed to barter raw materials for Chinese grain.)
The end of the North Korean state could also bring reunification of the Korean Peninsula under America’s ally South Korea, another development Beijing does not want. Also, the border itself could be put into question. South Korea has, in recent years, challenged China over the legacy of Koguryo, an ancient Korean kingdom whose rule extended into present-day China. The region is home to hundreds of thousands of ethnic Korean-Chinese, who face discrimination in China and might be sympathetic toward a reunified Korea making territorial claims.
Japan has 500,000 to 600,000 ethnic Koreans, descendants of those who arrived before or during World War II as forced laborers http://www.mercurynews.com/mld/mercurynews/news/world/15846382.htm Harassment of Japan's North Korean community, the biggest outside the homeland or China, dates back decades. But animosity has flared to new levels since North Korea stunned the world with its nuclear test. "Koreans who have nothing to do with the nuclear test have become the victim," Chongryon said. "The ratcheting up of sanctions severely threatens the rights and lifestyle of Koreans in Japan." All Koreans in Japan face discrimination. All were stripped of their Japanese citizenship after World War II. http://seattletimes.nwsource.com/html/nationworld/2003321601_nkorea25.html