It is difficult to say whether the DPRK has indeed conducted an H-bomb test because, going by international standards, it lags far behind in nuclear technology. But it has some nuclear capability.

The DPRK may claim to have developed nuclear weapons because of the threat from the United States, but that is only an excuse, because essentially it is trying to exploit the differences between China and the US.

More importantly, China rather than the US will be the biggest and most direct victim of the DPRK's nuclear program. The H-bomb test site, if indeed Pyongyang has conducted one, is just more than 100 km from the China-DPRK border along which on Wednesday many local residents felt tremors and some middle schools even suspended classes fearing an earthquake. And since Pyongyang conducted its previous nuclear tests also near the China-DPRK border, the threat to China is real.

In case of a nuclear leak, for instance, China's Jilin province that borders the DPRK will suffer the greatest damage owing to radiation and nuclear contamination.

Before Wednesday, the DPRK had conducted three nuclear tests, and each time the Chinese government or people urged it to abandon its nuclear program in exchange for more economic aid. But it seems the DPRK has made the nuclear program an integral part of its national strategy, as opposed to using it as a bargaining chip. In such a case, economic aid will only help the DPRK develop nuclear weapons, thwarting China's efforts to denuclearize the Korean Peninsula.

Zhang Lian'gui, a professor of international strategy studies at the Central Party School