In this photo, North Korean leader Kim Jong Un, right, joins hands and waves with visiting Chinese official Liu Yunshan, the Communist Party's fifth-ranking leader, during a parade in Pyongyang, North Korea, Oct. 10, 2015. China sees North Korea's claim to have conducted its first hydrogen bomb test on Jan. 6, 2016, as yet another act of defiance, boding ill for a relationship already under strain.
The hydrogen bomb is in fact already the global standard for the five nations with the greatest nuclear capabilities: the U.S., Russia, France, the U.K. and China. Other nations may also either have it or may be working on it, despite a worldwide effort to contain such proliferation.
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