"Of all princes, it is impossible for a new prince to escape the name of cruel, new states being always full of dangers... One ought to be both feared and loved, but as it is difficult for the two to go together, it is much safer to be feared than loved, if one of the two has to be wanting."
Niccolò Machiavelli, The Prince (1513)


Kim Jong-il, the North Korean leader who died in December, shunned the limelight, barely speaking in public during his 17-year rule. He never said whether it was because of the cruel treatment he received from wags like the makers of Team America and the Kim Jong-il Looking at Things blog.

His son Kim Jong-eun has seemed a relatively gregarious figure, giggling with generals after his maiden public address in April, and cheering his way through a concert last week that featured actors in Winnie the Pooh and Mickey Mouse costumes, clips from Rocky, and a rendition of My Way by one of North Korea's leading girl groups. He's even set gossip columnists' tongues wagging by stepping out with a glamorous former pop star (according to The Sun).

This week he showed his steelier side, sacking the 69-year-old army chief and childhood friend of his father's who had been his right-hand man since he took power. The official announcement on Monday said Ri Yong-ho was ill, but not a single analyst I spoke to gave this any credence. On the same day Kim issued a personal statement thanking soldiers for their loyalty - an apparent bid to stamp his personal mark on what is by far the world's biggest army per capita, with 1.2m troops in a country of about 24m people. Two days later it was announced that he had been promoted to Marshal, the highest military rank.

Writing about North Korea is a challenge unlike any I've come across before - it's probably more hermetically sealed, information-wise, than any other country in the world. The arrival there of mobile phones smuggled from China (those sold domestically can't phone abroad) has made it more leaky, and I'm still hopeful of doing a reporting trip there - although that will probably depend on a relaxation of the regime's currently sceptical attitude to visits by journalists, particularly ones based on this side of the border.

Fortunately there are plenty of people in South Korea with insights into the North, from visits there and lines of communication with people in the country - although even they stress the limits to what they can say with any certainty. Everyone I spoke to believed that the events of the past week showed a drive by Kim to secure his authority over the army, after speculation that his youth (he's about 29) meant he would be a figurehead for a government controlled by the geriatric generals who had surrounded his father.

One school of thought says that Kim Jong-il would always have intended his son to assert his dominance after a decent period of continuity in the top ranks. Philip Park, a professor at the University of North Korean Studies, disagreed, telling me: "Kim Jong-il's plan was to move to more collective leadership, because he knew that the monolithic leadership model would not be sustainable... Kim Jong-eun doesn't have any experience – if he tries to rule like his father, it could be a problem."

We may never know Kim Jong-il's dying wishes, but it should at least become clearer over the next few years what sort of leader his son intends to be. At any rate, as FT reader Age Olav Mariussen commented on our website, "it seems that Kim Jong-eun has read Machiavelli".

If so, Kim may be given food for thought by the following passage.....

Those who solely by good fortune become princes from being private citizens have little trouble in rising, but much in keeping atop; they have not any difficulties on the way up, because they fly, but they have many when they reach the summit.... Neither have they the knowledge requisite for the position; because, unless they are men of great worth and ability, it is not reasonable to expect that they should know how to command, having always lived in a private condition; besides, they cannot hold it because they have not forces which they can keep friendly and faithful.