Washington's recent revelation that North Korea has a nuclear weapons program has raised concerns around the globe, especially coming after months in which Pyongyang appeared to be reaching out to the rest of the world. North Korea has a long history of turmoil in its relations with South Korea and the United States.
Fighting in the Korean War halted in 1953, but the conflict, technically, is not over. The warring sides signed only an armistice, not a peace treaty.
Today, communist North and capitalist South Korea remain divided by a Demilitarized Zone running the width of the peninsula. On either side of the DMZ barbed wire and minefields are laid to deter invaders. The two countries have a million troops at the ready. More than 35,000 U.S. soldiers remain in South Korea, to help fight if the North attacks.
In the past five decades, relations between North and South have repeatedly swung from rapprochement to the brink of war. Almost every time the two governments edged closer, some event pushed them apart. And in most cases, the event was a North Korean action.
Scott Snyder is the Seoul-based representative for the Asia Foundation, a U.S. sponsored group which aims to foster democracy. He says that North Korea's hot-and-cold maneuvers are a well-calculated tactic. "Originally, North Korea was established by its founder Kim Il Sung who was a guerilla fighter against the Japanese. So I think he brought that type of mentality to the way that he governed. And indeed North Korea has always been a kind of guerilla state," he said.
Throughout the decades, North Korea sent spies into the South, attempting to kill national leaders. In 1968, North Korea seized the USS Pueblo, a U.S. spy ship, in international waters, and held its crew for a year.
Choong Nam Kim, a former adviser to three South Korean presidents, says that all of these events are examples of the North's efforts to overthrow the South's government. "Their unification strategy during the early decades, at least until the 1980s, was to win by force. That means building up their military. And secondly, by weakening South Korea. If a South Korean president is assassinated, there will be turmoil. They were attempting to destabilize South Korean society," Mr. Kim said.
But in the early 1970's, North and South Korea began a series of covert contacts. They surprised the world in 1972, pledging to peacefully pursue reunification.
In 1974 that pledge died, in part because a North Korean defector brought to Seoul maps of extensive tunnels the North was digging beneath the DMZ. The tunnels could be used to launch a surprise attack against the South.
In August 1976, North Korean soldiers nearly brought the two sides to war when they attacked a South Korean team pruning trees in the DMZ. Two American Army officers were killed with axes in the fight.
Relations hit a low point in October 1983, when Pyongyang tried to assassinate South Korean President Chun Do-hwan during a state visit to Burma. He survived, but several South Korean officials were killed by a powerful bomb planted by North Korean soldiers.
In the early 1990s, the North's already impoverished economy grew weaker, largely due to inefficient central planning. Despite food aid from the United States, South Korea, Japan and the United nations, a famine raged. Aid donors worried their offerings were going to the military instead of to the people.
Then another critical concern had also emerged: the North's suspected nuclear weapons program.
In 1992 North Korea allowed inspections by the International Atomic Energy Agency for the first time. But instead of winning praise, North Korea was accused of violating the nuclear Non-Proliferation Treaty, which it signed in 1985.
It blocked further inspections. But the United States and North Korea signed the Agreed Framework in October 1994, under which North Korea pledged to freeze its suspected nuclear program in exchange for two light-water nuclear reactors and supplies of heating fuel.
The pattern of progress and obstacles has continued in recent years.
In 1998, North Korea test fired a missile over Japan, showing it could easily hit the country with large weapons.
But in 2000, North Korea held an unprecedented summit with South Korea, agreeing to a series of projects to work toward reunification.
When President Bush took office, he ordered a policy review of North Korea and called the country part of an axis of evil nations pursuing weapons of mass destruction while its people were starving. Pyongyang responded by cutting off contact with South Korea and many of those projects came to a halt.
But this summer, North Korea again engaged in a series of diplomatic overtures resuming talks with the South, Japan and the United States.
That is when the latest crisis hit. During a visit by American envoy James Kelly in early October Washington says the North admitted, when confronted with U.S. evidence, that it had been pursuing a covert nuclear weapons program.
Former South Korean presidential advisor Choong Nam Kim says the admission does not surprise him. "Why at peacetime is North Korea talking about continuing their nuclear program? One (reason) might be a return to the old tactic of brinkmanship. In these months the American government is pressuring the Iraqi government, so North Korea is part of the evil axis, and they are afraid of attack," Mr. Kim said.
Scott Snyder of the Asia Foundation agrees. "To a certain extent these tactics are those of a state whose bark is worse than its bite and the louder the decibel level, the more it appears the DPRK (North Korea) may be trying to conceal some of its fundamental weakness," he said.
The United States says it wants to settle the issue peacefully. Pyongyang has indicated that it is willing to resolve the issue through dialogue, but only if Washington abandons what North Korea calls "hostile U.S. policy."
The revelation on North Korea's nuclear weapons program has sparked fears around the world. Once again, an unexpected move by North Korea has left the United States and its key North Asian allies, South Korea and Japan, doubtful about the communist state's motives and its willingness to abide by global agreements and the norms of international diplomacy.