In the Dear Leader's footsteps

North Korea’s threat of a "physical response" to joint U.S.-South Korean war games in the Pacific has thrust Kim Jong-il into the international spotlight once again.

Just as the bombastic North Korean leader has observers wondering how far he will go, his health has them wondering how long he will hold the reigns of power in his country.

He is thought to have health problems. Observers believe he's battling cancer or recovering from a stroke. There have also been reports of diminished mental capacities.

Fuelling speculation is the announcement that the North Korean Workers’ Party will hold its congress this year, for the first time since 1966.

As a result, speculation is rife about who will succeed the “Dear Leader.”

Though the regime’s activities are cloaked in secrecy, many observers think one of his sons will be tapped for the role. Here’s a look at who could be in line to take control of the Hermit Kingdom.

Kim Jong-nam, 39

He is the ruler’s eldest son. The young man’s mother is the late Korean movie star Sung Hae Rim, a mistress to Kim Jong-il who lived with him for two decades. She died in exile in Moscow in 2002.

The ruler’s father didn’t approve of the union, so the boy was hidden from public view. He was kept out of schools in Korea until his mid-20s. In 1998, he took on a senior post in North Korea’s domestic intelligence agency. He joined his father on a state visit to China three years later.

In May 2001, he was arrested in Japan while travelling with a forged Dominican Republic passport, and claiming he wanted to visit Disneyland in Tokyo. He was using a Chinese alias and was deported to China. The issue was embarrassing for Pyongyang, and is believed to have caused a rift between the young man and the “Dear Leader.”

Kim Jong-nam, a computer enthusiast who functions as head of the Korea Computer Center, is thought to be living in Macau, a special administrative region of China. Last year, he said he has no interest in succeeding his father as ruler of North Korea.

Kim Jong-chul, 28

He is the ruler’s middle son. His mother is Ko Young Hee, a former dancer and the ruler’s third wife.

Kim Jong-chul was educated in Switzerland, where he apparently developed a fondness for the music of Eric Clapton. He is thought to be fluent in English and German.

Three years ago, he was given a high-ranking position in Korea’s Workers’ Party. However, he is not thought to be earmarked as the ruler’s successor. Kim Jong-il’s former chef wrote in a memoir that the ruler thought his middle son was not a good choice because he’s like “a little girl.”

Kim Jong-un, 26

The second son of Kim Jong-il and Ko Young Hee, this young man is widely expected to be the next ruler of North Korea. Apparently, the “Dear Leader” views him as more politically astute than his older brother – and more masculine.

Kim Jong-un reportedly attended school in Switzerland, but those reports have been disputed. Between 2002 and 2007 he attended a military academy in Pyongyang.

He is also thought to speak German, English and French. According to some reports, he is a basketball fan but is overweight, diabetic and prone to health problems.

Two years ago he was reported to be working in the Korean Workers’ Party or the army’s political bureau. Both departments are involved in surveillance and monitoring government officials. Earlier this year he was appointed to the country's powerful National Defence Commission.

The young man hasn’t been photographed since he was 11 years old, but has been described as the spitting image of his father.

Chang Sung-taek

Married to Kim Jong-il’s sister, Chang is director of the administrative department of the North Korean Workers Party. Some analysts predict he will take over from the “Dear Leader” and stay in that position until Kim Jong-un is ready to assume the mantle of power, acting as a bridge between father and son.

The political life of North Korea's leader, Kim Jong Il on Dipity.