North Korean leader Kim Jong-il is likely basking in the patriotic fervour whipped up by his nuclear test but is too worried about his own well-being to start a war, North Korean defectors said on Thursday.

Poverty, famine and political oppression have driven tens of thousands of North Koreans over the border to seek a better life.

"Why did they have to do it again? If they already have all that military power, perhaps it would be a wiser plan to make the lives of the people better," a defector named Choi told reporters at a centre established by the South to help recent arrivals adjust to life in their new capitalist home.

The defectors asked to be identified only by their family names because the North is known to punish relatives of
escapees.

The communist North, facing international censure for this week's nuclear test, has threatened to attack the South after it joined a U.S.-led plan to check vessels suspected of carrying equipment for weapons of mass destruction.

"All Kim Jong-il thinks about is himself and because of that, he won't start a war," said Cho, another defector, echoing the comments of several others.

The defectors are among about 14,000 who have passed through the Unification Ministry's Hanawon centre in the town of Anseong, south of Seoul, since it was set up about 10 years ago.

The North's only prior nuclear test in 2006 "felt like a grand celebration," said Kim, another defector who was in the
state at that time.

Despite Kim Jong-il's guiding principle of putting the military first, many of the North's 1.2 million troops are ill-equipped and underfed, the defectors said.

"The soldiers were meant to fight a war but the ones I have seen will probably run away," said defector Kim.

Analysts said the North's sabre rattling might be partly aimed at firming the leader's grip on power and helping him
draw up succession plans in Asia's only communist dynasty after a suspected stroke in August raised questions over his rule.

Several defectors said their former leader, called "a peerless military genius" by state propaganda, has lost a great
deal of weight, with one saying: "The general has aged a lot."

Several said they had no idea Kim had three sons because the state does not allow discussions of his family life.

This could complicate succession because Kim was well known for decades at home before taking over after his father Kim Il-sung died in 1994, and even then, it took the well-groomed younger Kim several years before he was firmly in control.