The war between the Koreas never formally ended. It was put on hold by an armistice. The United States and South Korea say a long series of provocative moves by Pyongyang during the past 50 years have increased the risk hostilities could reignite. Kurt Achin takes a historical perspective.
On July 27, 1953, an armistice ended hostilities in the Korean War, a three-year conflict that left more than one million soldiers dead or missing and, according to some estimates, claimed the lives of as many as three million civilians.
North Korea drew back to its original side of the border on the Korean Peninsula. The warring parties set up a Demilitarized Zone, a no-man's land that still separates the two countries. North and South Korea have moved to the brink of renewed fighting several times during the past five decades.
North Korean leaders have made it clear they consider South Korea and its allies, particularly the United States, threats to the continued existence of their communist nation. Acting on that conviction, they have tried to destabilize the South Korean government and provoke Washington, which maintains about 37,000 U.S. troops near the North's southern frontier.
Twice, North Korea tried to kill former South Korean President Park Chung-hee, in 1968 and again six-years later. Although Mr. Park escaped, his wife was killed in the second attack.
In 1983, two North Korean military officers confessed to planting a bomb at a South Korean diplomatic event in Burma. The Asia Program Director at the Woodrow Wilson International Center for Scholars in Washington, Robert Hathaway, recalls 17 South Korean officials, including the foreign minister, were killed by the blast.
"… and which, except for the fact that the South Korean president was running late, would have probably killed the South Korean president, as well," he explained. "That is perhaps the most egregious, but certainly not the only, incident of that sort."
In 1987, a Korean Airlines Boeing 707 exploded in midair, killing all 95 passengers and 20 crew members. A captured North Korean agent confessed she and a colleague set the bomb to scare sports fans from attending the 1988 Olympics in Seoul.
And in 1998, the North fired a ballistic missile over central Japan, alarming northeast Asian governments and the United States. Pyongyang has resorted to kidnapping to serve its plans. In September 2002, Pyongyang stunned the world when it admitted to kidnapping 13 Japanese citizens in the 1970's and 1980's, to force them to train spies.
South Korean authorities have discovered four tunnels leading from North Korea, big enough to allow hundreds of thousands of troops to cross into the South. Seoul also accused the North of provoking a number of naval clashes in the South's waters, but Pyongyang returns the accusation. And Seoul has caught Pyongyang slipping spies across the border, sometimes using submarines.
But South Korea and the United States also actively spy on the North, something Pyongyang considers threatening.
Michael Breen is a Seoul-based businessman and former journalist who authored the book The Koreans: Who They Are, What They Want, Where Their Future Lies. He says provocation is not a one-way street, although North Korea deserves most of the blame.
"In a sense they [North Korea]consider the continuing U.S. presence in South Korea as a sort of provocative positioning if you like," he said. "There are also stories, and I do not know how true they are, … but the assassination attempts on South Korean presidents were actually retaliations for what were understood to be provocations by South Korea.
Even after, I believe, American spy planes started flying over North Korea, which is another provocation by the way, South Koreans used to send in spies, you know agents, soldiers, to go and scope things out," he continued. " When they got caught, which apparently they did with some frequency, again that would be interpreted as a provocation. That is not to excuse the North Koreans, for every hundred incidents, they are guilty of 99 of them."
In recent years, tensions between Pyongyang, Seoul, and Washington have centered mainly on North Korea's nuclear ambitions. The North's leaders say their country needs nuclear weapons to deter an invasion by the South and its U.S. allies.
In the early 1990's, North Korea threatened to withdraw from the global nuclear Non-Proliferation Treaty and refused to allow international inspectors to ensure it was not producing nuclear bombs.
By late 1993, there was talk of a U.S. military strike to destroy Pyongyang's nuclear facilities. A visit by former U.S. President Carter in mid-1994 helped end the deadlock. Eventually, North Korea promised to give up its nuclear program, in return for energy aid from the United States.
But during the past several months, North Korea has abandoned its international pledges to stay nuclear free, and admitted having a program to build nuclear bombs.
The Executive Director of the American Chamber of Commerce in Seoul, Tami Overby, recalls a recent incident when North Korea's defense minister threatened to turn Seoul into a "sea of fire."
"That was probably the most tense in my 15 years here, where people actually were running out and buying ramen, which are the dried noodle soup mix, and bought water just as a precaution," she said.
North Korea has resisted pressure from the United States, South Korea, Japan, and China to give up the nuclear development program. It says it first wants a non-aggression pact with Washington.
Though Washington has said repeatedly it has no plans to attack North Korea and it is determined to reach a peaceful solution, it has resisted demands for a formal non-aggression pact or bilateral negotiations without the participation of North Korea's neighbors.
In the meantime, the frontier between North and South Korea remains one of the world's most dangerous flashpoints, one that could easily trigger a major war, possibly a nuclear exchange.