International condemnation has followed North Korea's claim it has successfully tested a hydrogen, or "H," bomb. If confirmed, such a test would mark a major upgrade in North Korea's capabilities. But there are questions about the claim. Yin Wu reports.
International condemnation has followed North Korea's claim it has successfully tested a hydrogen, or "H," bomb. If confirmed, such a test would mark a major upgrade in North Korea's capabilities. But there are questions about the claim. Yin Wu reports.
