When North Korea first hinted it had a hydrogen bomb, it was dismissed rather hastily and was not considered an actual threat. Even now, after being told that the isolated country has successfully tested a miniaturised hydrogen nuclear device, there is still scepticism among experts and officials. These sources doubt Pyongyang has actually managed to achieve such a major advance in its strike capability, yet the North Korean establishment is probably the most proficient in the world in terms of calculating the benefits and risks of ratcheting up tensions and alienating even its closest allies to get what it wants.
The nuclear test comes just a few months ahead of what is scheduled to be the seventh congress of the country's ruling party, which was founded 70 years ago, and two days before what is believed to be Kim Jong-un's birthday; he is understood to be in his early 30s.
Kim Jong-un has gone to great lengths to conceal his true intentions – just as he strives to seem powerful and important in the photos released by the North Korean Central News Agency (KCNA) where he is constantly surrounded by employees who are either rapidly taking notes, laughing (for a reason that is usually unknown) or watching his every move.
While North Korea uses its nuclear tests to project power abroad, they are also a domestic propaganda tool for its third-generation dictatorship.
The years since Kim Jong-un took power following his father Kim Jong Il's death in 2011 have been turbulent, marked by high-level purges and irrational executions.
Speaking about the nuclear test, which was conducted at 10am local time (01:30 GMT), according to North Korea's official KCNA news agency, Kim wrote, in what North Korean state TV displayed as a handwritten note, the words: "Let the world look up to the strong, self-reliant nuclear-armed state."