|Kim Jong-il may have an urgent need for aid, and the artillery barrage may be his way of demanding it [REUTERS]
North Korea fired dozens of artillery shells at a South Korean island on Tuesday, setting dozens of houses ablaze in the heaviest attack in the region since 1953.
South Korea said four people were killed in the confrontation, and Ban Ki-moon has called it "one of the gravest incidents since the end of the Korean War."
Was North Korea's shelling a pre-meditated incident?
Experts don't agree on the exact reasoning behind North Korea's decision to assault the South Korean island of Yeonpyeong in the Yellow Sea.
North Korea's military and government are on a permanent war-footing and view military manoeuvres by South Korea and the US with alarm.
South Korea's armed forces have been holding military exercises and were conducting live firing drills in the vicinity of the disputed islands. So, it is possible that nervous North Korean officers misinterpreted, believing they were under fire.
But analysts see this as unlikely. Such drills are routine, and there appears to be nothing unusual that could have caused a misunderstanding. Also, the North's response came at least half an hour after the live firing exercise ended.
It is more likely that the attack was planned in advance but that Pyongyang used the South Korean drills as a pretext. This would allow the North to claim self-defence, and indeed North Korea was unusually quick in issuing a statement saying Seoul was the aggressor.
How would the North benefit from blackmail?
For decades, North Korea's leadership has tried to get what it wants from world powers through bouts of bad behaviour, followed by promises to stop making trouble - in return for more concessions.
It is a strategy that has been highly successful. Repeatedly, Pyongyang has agreed to sweet deals with the US and its allies, only to abandon them when they cease to be useful.
"I don't expect the situation to further escalate, because North Korea has already achieved its goal of getting everyone's attention," said Xu Guangyu, a retired major general in the Chinese army, who now works for the government-run China Arms Control and Disarmament Association.
The North may well attempt more provocations to bolster its bargaining position and increase its leverage. Additionally, a third nuclear test certainly cannot be ruled out.
Do the people of North Korea expect military assertiveness?
North Korea has entered a potentially long and an unpredictable period of leadership transition, with the elevation of Kim Jong-il's youngest son, Kim Jong-un, to the rank of general in a clear signal that he is the chosen successor.
"Over several decades, North Korea has created similar geopolitical tensions in order to redirect their national interest to defence"
Young Chang, UBS analyst in Seoul
The media has begun celebrating Kim Jong-un as "the young general" - even though his military experience appears to be practically nonexistent.
The unveiling of a clear succession plan may have led to internal conflicts and sparked anger among other powerful and ambitious members of the military and political elite.
The fact that Kim Jong-il is rushing his succession plan due to ill health adds to the unpredictability.
The artillery attack, therefore, may have been an attempt to show off the military credentials of the "young general" and win him more support among the armed forces.
It also could be seen as an effort by Kim Jong-il to deal with internal dissent by focusing attention on a supposed external threat -- South Korea and its allies.
In this scenario, the risk of war is also extremely low, because Pyongyang's provocations are calculated to boost support at home without sparking a major conflict that the regime does not want.
"Over several decades, North Korea has created similar geopolitical tensions in order to redirect their national interest to defence, which we believe helps the regime maintain power," Young Chang, a UBS analyst in Seoul, said.
Could the North soon receive more international aid?
North Korea's economy has been struggling for decades, and the leadership's "military-first" policy of putting the interests of the huge military ahead of human necessities has taken a massive toll in terms of famine, malnutrition and misery.
A botched currency reform last year significantly worsened the plight of ordinary North Koreans and provoked rare signs of dissent. Food production this year is believed to have been badly hit by flooding.
The government has survived in the past, despite inflicting mass starvation on its people. But if hardship is also now affecting senior members of the military, there may be an element of desperation in the attack.
Can the military brass make independent decisions?
One of the most worrying scenarios is that Monday's artillery attack, and the sinking of the corvette Cheonan in March, were not approved by Kim Jong-il, but were the work of disaffected groups in the military who are increasingly acting on their own.
This theory is supported by Christopher Hill, former US envoy to North Korea, who says the North Korean military is unhappy about Kim Jong-un's planned succession and is driving events without direction from Kim Jong-il.
"With the ongoing leadership transition in North Korea, there have been rumors of discontent within the military, and the current actions may reflect miscommunications or worse," Hill said.
What are the biggest risks involved?
The biggest risk is that North Korea's transition and economic problems result in the leadership making risky moves that go beyond the provocations of the past and cause events to spiral out of control.
With Kim's health uncertain, his son still an unknown quantity, the delicate balance that has for decades kept the peninsula tense but peaceful may be unravelling.
While neither side wants war, there is always the risk that misunderstandings or miscalculations could lead to unintended conflict.
The other major risk to South Korea is what happens when North Korea's regime collapses.
That prospect is regarded with dread by many policymakers because of the enormous economic costs and sudden chaotic reunification of the two Koreas would impose on the region.