The nuclear test carried out by Pyongyang on September 3rd, the sixth led by the regime over the last decade, has exacerbated international concern over possible atomic proliferation in the Pacific. With an estimated power of 120 kilotons, the experiment seems to have allowed the North Korean government to test a thermonuclear device, five times higher than the one tested last year. Although the claims of the regime of developing an hydrogen bomb, that is superior for explosive potential to traditional atomic weapons, has not been confirmed yet, the apparent development of thermonuclear technology and double-stage atomic weapons has put in highlight the rapid progress made by Pyongyang's research program.
 In 2016, North Korea conducted two nuclear tests: on January 6, with an estimated power of between 7 and 10 kilotons and on September 9th, with an estimated power of 20-30 kilotons.
 The hydrogen bomb (or H bomb or thermonuclear bomb) is based on two linked phases: a first nuclear fission (powered by uranium or plutonium), which triggers a second nuclear fusion reaction (of hydrogen isotopes). The simplest model is formed by a device enclosing the fission bomb next to the combustion fuel.