More and more, fingers are pointing at North Korea, though Pyongyang continues to deny involvement. South Korea's Defence Minister Kim Tae-young said after the lifting of the last part of the vessel that it had been riven after an explosion caused by a torpedo, though he didn't say where from. President Lee has vowed a resolute response, if its proved the North was involved.
Presenter: Linda Mottram
Lee Jung Hoon, Professor of International Relations, Yonsei University, Seoul; Daniel Pinkston, North East Asia deputy project director, International Crisis Group, Seoul
MOTTRAM: The magnitude of the disaster near a disputed sea border between South and North Korea was on public display as the country's President Lee Myung Bak joined ordinary citizens paying tribute at a new memorial. Pyongyang continues to deny that it attacked the Cheonan, killing 46 sailors. Seoul continues assembling evidence. If the South proves the North's role, Professor of International Relations at Yonsei University, Lee Jung Hoon says the implications are very serious.
LEE: Wars have erupted over much smaller events.
MOTTRAM: But even with a long history of North Korean provocations, Professor Lee is not forecasting war.
LEE: I believe that we will appeal to the UN Security Council. There are a number of projects that the South Korean government and private ventures are conducting in North Korea including the Kaesong Industrial Park where there are Korean businesses as well as tourism. Under the circumstances to continue with these projects whilst our ship's been under attack by the North Koreans, it just doesn't make sense.
MOTTRAM: Daniel Pinkston is based in Seoul as the North East Asia deputy project director for the International Crisis Group. He broadly agrees with Professor Lee.
PINKSTON: I don't think there's going to be any military retaliation or anything like that. There's no benefit to escalating. But as far as inter-Korean relations, restarting of six-party talks, returning to diplomacy to try to resolve some of the tensions in the region I think that's going to be delayed and it could take six months, a year easily, if not longer.
MOTTRAM: Daniel Pinkston also says it's likely that under their security alliance, the U-S and South Korea will delay a planned 2012 handover of joint operational control to South Korea alone while he also predicts South Korea might abandon an inter-Korean maritime agreement that saves on fuel costs for the North by allowing shorter routes for some of its shipping.
Professor Lee says the six party talks on denuclearising Pyongyang may resume again at some time. They've been stalled since North Korea walked out a year ago, a month before its second nuclear test. But he says they've clearly failed in their main aim, since the North now brags that it is a nuclear power.
LEE: If we really want to put a stop to further North Korean nuclearisation and the continuing of the threat of the use of force, much more stern measures have to be taken by the international community to put a check on North Korea and to do so I think its very important to convince China to get China on board.
MOTTRAM: The Crisis Group's Daniel Pinkston says China has been implementing military sanctions, but will probably continue to be a weak point on other sanctions.
PINKSTON: Luxury goods which are also part of the sanctions regime, some of the other trade that China views as normal trade, I don't think they're going to block that type of economic transactions across the border.
MOTTRAM: These issues are likely to be discussed when the South Korean and Chinese Presidents hold a summit on the sidelines of the World Expo which opens in Shanghai later this week.
In the meantime, the New York Times has reported that a North Korean newspaper has published a photo of the ailing leader Kim Jong-il and another young figure, that could be, some experts say, the annointed heir, the elder Kim's little-known and never-before-seen third son, Kim Jong-un. Professor Lee Jung Hoon again.
LEE: There's been in the past, especially by the Japanese press, releasing photos, alleged photos of Kim Jong-un, but they've all proven to be false photos so the current one, especially if its published by the North Korean Press Agency then it's very interesting.
MOTTRAM: As with the past practice of Kremlinology .. observers trying to decipher the secretive political machinations of the Soviet leadership .. the photo will doubtless be poured over further. There'll be little illuminating though coming from the fortune-teller said to be a favourite among Pyongyang elite and responsible for a prediction that by the sixteeth of May this year, Kim Jong-il would die or be near death. In a country where such predictions are considered blasphemy, a Korea Times report citing other agencies says the fortune-teller has been missing for three weeks.