US SECRETARY of state Hillary Clinton described the security situation between the two Koreas as "highly precarious" following the North's sinking of the South Korean warship Cheonan.
“We are working hard to avoid an escalation of belligerence and provocation,” Mrs Clinton told reporters during a visit to Beijing. “This is a highly precarious situation that the North Koreans have caused in the region.”
She said the Obama administration was working hard to stop tensions escalating in what is one of Asia’s flashpoints. The US maintains a force of 28,500 troops in South Korea, with most of them stationed along the demilitarised zone that divides the peninsula.
The sinking of the Cheonan, near the maritime border dividing the two Koreas to the west, was South Korea's worst military disaster since the 1950-53 Korean War.
An international team of investigators said last week that a torpedo fired from a North Korean submarine tore the vessel in two.
Mrs Clinton said North Korea’s neighbours would consider sanctions and this would appear to include China, North Korea’s ally.
Beijing has so far refrained from criticising the North, which it backed during the war, and repeated its call for all sides to exercise "calm and restraint". The Cheonanincident should be handled "fairly and objectively . . . like other international issues", foreign ministry spokesman Ma Zhaoxu said.
South Korean president Lee Myung-bak has demanded that North Korea apologise, punish those responsible and “most importantly, stop its belligerent and threatening behaviour”.
Mr Lee said his country would no longer tolerate the North’s “brutality” and said the repressive communist regime would pay for the surprise March 26th torpedo attack that killed 46 sailors, about half the crew.
He also vowed to cut off all trade with the North and to take Pyongyang to the UN Security Council for punishment over the sinking.
The incident has incensed public opinion in South Korea, with television running footage since early on of weeping mothers and children. President Lee however was careful to insist on a full investigation to establish beyond doubt that the incident was indeed an attack and to allow inflamed public tempers time to cool.
Pyongyang's response when threatened by the South is to promise all-out war. True to form, it responded with defiance, saying that accusing it of blowing up the Cheonanwas tantamount to declaring war. The North Koreans have also said they will open fire on speakers if the South resumes blaring anti-North Korean propaganda back over the border, which was abandoned in 2004 as relations thawed.
There have been numerous attacks on South Korea over the years. North Korea is suspected of involvement in a 1983 attack on a presidential delegation that killed 21 people and the bombing of an aircraft in 1987 that claimed 115 lives.
Pyongyang disputes the maritime border unilaterally drawn by UN forces at the close of the war, and the Koreas have fought three bloody skirmishes there, most recently in November.
In Seoul, defence minister Kim Tae-young said the US and South Korea would hold joint anti-submarine exercises in the waters soon. Joint military exercises are guaranteed to anger the North Koreans.
Trade relations between the two countries show how complicated the relationship between the two Koreas is.
Despite their rivalry, Seoul was North Korea’s number two trading partner with €1.36 billion in trade in 2009. The biggest source of trade – a joint factory park in the North Korean border town of Kaesong where some 110 South Korean firms employ about 42,000 North Koreans – will remain open. It recently reopened after the North closed it during an earlier fit of pique.