How to resolve the Korean crisis

The sudden flare up of violence on the Korean peninsula is extremely worrying. South Korea is now on its highest peacetime alert. This is one of the most dangerous situations since the 1953 Korean War armistice (there is still no peace treaty).

We don't know for sure why North Korea decided suddenly to attack the island of Yeonpyeong on November 23 2010, in the disputed boundary waters to the west of the Korean peninsula. Certainly there had been no direct provocation to the North.

There may be some sort of domestic power struggle underway. North Korea's Kim Jong-il is in poor health and he is believed to be grooming his son Kim Jong-un to replace him. Perhaps the North Korean military - the most powerful bloc in that failing state - is running with its own agenda.

Alternatively perhaps Kim Jong-un is trying to show his toughness by goading the South and so prove to his citizens - and the military - that he is as ruthless as his father and late grandfather (Kim il Sung).

This attack is the third dramatic military development this year. In March a South Korean warship was sunk in these waters. It is assumed that the attack was done by North Korea (which denies doing so). 46 South Korean sailors were killed.

Last weekend an American scientist on a visit to North Korea found the nuclear facilities more advanced than the international community had suspected. North Korea still does not have a complete nuclear capacity - but it is making progress towards that goal.

Now there is this unprovoked attack on South Korea, in which a further two people were killed.

Meanwhile the South Koreans are being urged by other governments to avoid escalating the violence.

In fairness, the South Koreans could well claim that they are being pushed beyond a reasonable point: two military incidents have so far this year caused the death of at least 48 military personnel.

How much more restraint should they be expected to show? If they don't respond, what is to stop North Korea from continuing to push the envelope? Where and when will the next attack come? Does the lack of a South Korean response show weakness to the North Koreans?

Standing back from this immediate attack, there is the broader issue of how the international community is to respond to this type of development (Iran's nuclear ambitions pose a similar dilemma).