IF A North Korea war does become a reality, one unmanageable $3 trillion consequence that hasn’t been widely acknowledged threatens to wreak havoc on the world.

The defiant nation launched another missile test today, just hours after stern warnings from Donald Trump that a “major, major conflict” was possible.

The conflict between Kim Jong-un and Donald Trump could unfold in several ways, but it is the 25 million citizens of the hermit state whose fate could trigger a global catastrophe.

A thermonuclear war would be a humanitarian and ecological disaster for the entire region, with radiation causing a nuclear holocaust that tears into South Korea, China, Russia and Japan.

But if conventional weapons are used and the Kim regime collapses (a more likely scenario), we may face an alternative nightmare.

‘NO SPACE FOR THE KIMS’

The first consequence would be that the Kims and all those connected with the ruling Workers’ Party of Korea would have to flee compatriots angry at years of human rights violations and public executions.

“Secret police and party officials would seek refuge in neighbouring China or Russia,” Australian National University researcher Leonid Petrov told news.com.au. “There’s no space for the Kim clan in a unified Korea, his brother, cousin, aunts and uncles, they are inseparably connected with the regime and will be prosecuted as criminals.

“Some South American countries might be willing to give refuge to people — Bolivia, Venezuela, Guatemala ... countries that are anti-American might be supportive.”

So what will Kim Jong-un’s people do without their supreme leader? With a lack of money, food and shelter if the regime collapses, they too may seek refuge in China, Russia and South Korea, but those countries will not necessarily be open to an influx of North Korean refugees.

THE 25 MILLION PERSON PROBLEM

China is already home to an estimated 100,000 North Korean defectors, and is unlikely to want the pressure of more. The Chinese have been concerned about such a scenario for some time, and might reinforce the border with troops, Rand Corporation scientist Andrew Scobell told Foxtrot Alpha.

Others may try to travel from city to city in search of refuge, while others could try to cross into South Korea, although if fighting persists in the DMZ, that would be almost impossible.

The most likely conclusion would be the reunification of Korea, according to Dr Petrov, but this may mean deep economic and social problems.

“The South Korean economy is reaching crisis,” he said. “It needs to urgently access cheap resource and labour.

“South Korea might use the opportunity to exploit North Koreans who have less education or experience in enterprise. Millions of North Korean workers could become second class citizens, there could be widespread discrimination, even the border might be kept for years to stop mass immigration. It will take at least a decade before the level of prosperity will be equalised between North and South. During that 10 years, the reunification is going to be very expensive, $3 trillion or more. There’s going to be definite social tension between South Koreans and North Koreans.

“Both countries have been isolated from each other, they speak different dialects, understand the world differently. South Korea doesn’t need its impoverished, aggressive, poorly educated brothers to inundate South Korea.”

‘A CRASH LANDING’

The reunification of Korea has been under debate for years, and former South Korean president Kim Dae-jung won the Nobel Peace Prize in 2000 for his implementation of the Sunshine Policy to improve political relations between the two states.

But in 2008, the new conservative government put an end to the process, and experts now fear a “crash landing” rather than a soft one. “The East and West Germany unification is a walk in the park compared to what is going to happen in North and South Korea if a reunification happens uncontrollably,” said Dr Petrov. “It will be a huge sociological and demographic issue.”

Korea might expect abuse, crime and other social problems. And the US could feel the consequences too.

“South Korea would probably not support America in open military stand-off against North Korea,” said Dr Petrov. “The America-South Korea alliance will melt away.

“Economic growth in North Korea means more opportunity for South Korea to access natural resources, cheap labour and transport projects (e.g. linking South Korean railways with China).”

He said the experience could be a “bonanza” for both states, as opposed to “military action with catastrophic consequences for both.”

South Korea is due to hold a presidential election on 9 May. If left-wing Moon Jae-in should win, reunification looks likely and the power of the US will take the hit it dreads.

emma.reynolds@news.com.au