JIM LEHRER: Now: the latest on the crisis between North and South Korea and what the United States should do about it.
U.S. PRESIDENT BARACK OBAMA: You have my blessing.
JIM LEHRER: President Obama began his day with the ceremonial Thanksgiving turkey pardon, never addressing the issue of the escalating tensions on the Korean Peninsula.
But, last night, after an emergency session at the White House, the president agreed to stage joint military exercises with South Korea in the Yellow Sea this weekend. It's the United States' first military response to North Korea's deadly shelling of a South Korean island Tuesday morning.
The U.S. is sending the carrier George Washington to the region. More than 28,000 American troops are already stationed in South Korea. Prior to making the call, the president stressed the United States commitment to South Korea in an interview with ABC News.
BARBARA WALTERS, ABC News: Is an attack on South Korea an attack on the U.S.?
BARACK OBAMA: South Korea is our ally. It has been since the Korean War. And we strongly affirm our commitment to defend South Korea as part of that alliance.
This is a just one more provocative incident in a series that we have seen over the last several months.
JIM LEHRER: Today, the chairman of the U.S. Joint Chiefs of Staff, Admiral Mike Mullen, increased pressure on China, North Korea's strongest ally, to stand firm.
ADMIRAL MICHAEL MULLEN, chairman, Joints Chiefs or Staff: The one country that has influence in Pyongyang is China, and so their leadership is absolutely critical.
JIM LEHRER: The decision to send U.S. forces came as South Koreans remain on high alert, one day after a North Korean barrage hammered Yeonpyeong, a tiny island off the South Korean coast.
Today, rescuers there found the burned bodies of two civilians killed in the attack. The shelling also killed two South Korean marines and wounded 18 people. About 1,700 civilians live on the island, home to a South Korean military base. Today's images revealed the scope of the destruction.
MAN (through translator): The bomb fell just fifty meters from me. I was going to turn around, but I didn't, because I was reaching out for something in front of me instead. And, at that moment, the bomb dropped.
JIM LEHRER: More than 500 evacuees streamed into the port city of Incheon, after spending the night in underground shelters.
WOMAN (through translator): I thought, oh, this is not another exercise. It is a war. I decided to run. And I did.
JIM LEHRER: Tuesday's attack by the North was the most severe since the Korean War ended in 1953, and marks the first time civilians have died in the stalemate since the bombing of a South Korean airliner in 1987.
The incident also dramatically escalates an already tense year on the Korean Peninsula. In March, a South Korean warship was hit by a torpedo on a routine patrolling mission. Fifty-six sailors were killed. North Korea denied any responsibility.
And, earlier this week, North Korea revealed an advanced uranium enrichment facility. The North Korean government has long refused to negotiate on nuclear issues, but has hosted three American delegations in the last month.
For his part, ailing North Korean leader Kim Jong Il again made no comment on the growing tension. He spent the day touring a university with his youngest son, and heir apparent, Kim Jong-un.