JIM LEHRER: Finally tonight: that bloody 1950s conflict in Korea called the forgotten war.
Jeffrey Brown has our story.
JEFFREY BROWN: In Korea today: stark reminders of tensions past and present for two American officials, Secretary of State Hillary Clinton and Secretary of Defense Robert Gates.
They got a firsthand look across the 160-mile heavily armed line that divides North and South, the demilitarized zone along the 38th Parallel.
MAN: You see that brown tower, that's one of the Korean guard posts that's manned by about 30 North Korean soldiers.
JEFFREY BROWN: Secretary Gates, who had been to the DMZ twice before, noted there had been little progress across the border.
ROBERT GATES, U.S. secretary of defense: Looking out across the DMZ, it's stunning how little has changed in the North, and yet how much South Korea has continued to grow and prosper.
JEFFREY BROWN: In fact, if anything, tensions have increased in recent months. The U.S. and South Korea will soon begin joint military exercises. And, in Seoul, the two Americans held security talks with their South Korean counterparts and announced new sanctions against the North, which the U.S. says is pressing ahead with its nuclear weapons program.
HILLARY RODHAM CLINTON, U.S. secretary of state: These measures are not directed at the people of North Korea, who have suffered too long due to the misguided and maligned priorities of their government. They are directed at the destabilizing, illicit, and provocative policies pursued by that government.
JEFFREY BROWN: Those provocations include the March 26 sinking of a South Korean warship, the Cheonan, in the Yellow Sea, in which 46 sailors on board were killed.
After the ship was raised, an international investigation concluded that a North Korean torpedo attack had sunk the ship. North Korea denied any involvement, and its state television broadcast images of protests against the U.S. and South Korea.
Today's official visit was also part of a remembrance of the 60th anniversary of the start of the Korean War that began with a surprise attack by at least 90,000 North Korean troops, with backing from the Soviet Union, on June 25, 1950.
NARRATOR: High overhead, U.N. planes roam the skies almost at will.
JEFFREY BROWN: The U.N. Security Council voted to defend the South with a multinational force. And President Harry Truman, without asking Congress to declare war, committed U.S. soldiers to what he would call a police action.
Poorly trained and equipped American troops rushed to the peninsula from occupation duty in Japan, where they were first quickly pushed deep into the South by the North Koreans. Months later, the tide turned with an amphibious landing at Inchon, and the 15-nation U.N. force led by American General Douglas MacArthur routed the Northern armies almost to the Yalu River.
That, in turn, drew in massive armies of Communist Chinese, who sent the allied forces into a hasty winter retreat. General MacArthur called for carrying the fight into China, but was overruled and fired for insubordination by President Truman, in one of the great tests in American history of civilian control of the military.
The war then settled into a stalemate along the 38th Parallel and ended in an armistice on July 27, 1953, but never in a formal peace treaty. For years, the official American combat death toll was set at some 56,000. But, in 2000, the military revised the actual combat toll to 37,000. Hundreds of thousands of South and North Koreans, as well as Chinese troops, died in the conflict.
Long known as the forgotten war, sandwiched between the definitive victory of World War II and the trauma of Vietnam, the Korean conflict was honored with its own memorial on the National Mall in 1995.