The World War II Japanese occupation of the Korean Peninsula ended in 1945 when the United Nations gave control of the North to the Soviets and the South to the United States. Separate nations â€“ North Korea and South Korea â€“ were established in 1948. But North Korea, seeking unification, invaded the South in 1950, sparking the Korean War in which the UN supported the South, and China and the Soviet Union backed the North. The uneasy cold-war legacy of confrontation-rapprochement-confrontation has characterized the past half century:
1968 North Korea seizes the USS Pueblo, a Navy spy ship; its crew of 83 is released 11 months later.
1969 North Korea shoots down a US spy plane over the Sea of Japan; its 31-member crew perishes.
1976 In the "ax murder" incident, North Korean troops kill two US Army officers as they prune a tree in the demilitarized zone to improve surveillance.
1988 US imposes sanctions on North Korea, which is added to a list of state sponsors of terrorism.
1989 US satellite photos show a nuclear reprocessing plant in Youngbyon.
1998 North Korea launches its first long-range ballistic missile.
2005 North Korea says, for the first time, it has nuclear weapons.
2006 North Korea conducts its first nuclear test.
2007 Passenger trains traverse the North-South border for the first time in more than 50 years.
2008 North Korea dynamites a cooling tower at its Yongbyon nuclear facility as a commitment to "denuclearization." The US later removes North Korea from its list of terrorist nations.
2009 North Korea arrests two US journalists at the Chinese border, sentencing them to 12 years of hard labor. Former President Bill Clinton travels to North Korea and wins their release.
In April, North Korea launches a long-range rocket and announces intent to quit the six-party talks. A second nuclear test is conducted in May, which draws further UN sanctions. Ballistic missiles launched in July.
2010 In January, North Korea imprisons Aijalon Gomes, an American who taught English in South Korea, after he crosses the border. Mr. Carter helps negotiate his release in August.
In March, a North Korean submarine fires a torpedo at a South Korean naval ship â€“ 46 sailors die.
In November, North Korea shells a South Korean island near the disputed Yellow Sea border, killing two South Korean marines and two civilians. Days later, the US and South Korea proceed with scheduled war exercises in the Yellow Sea.
Compiled by Leigh Montgomery
Sources: CQ Researcher, Congressional Research Service, Freedom House,Wire reports