Besides China, there are other sources North Korea can have used to aquiver this technology. Both North Korea, Libya, Iran and China did get help developing nuclear technology from a network set up by Abdul Qadeer Khan, a Pakistani nuclear physicist often regarded as the fonder of the Pakistani nuclear enrichment program.<p>He again acquired the technology in Europe when working for Urenco, a nuclear fuel company.<p>The whole Q.A Khan affair is quit a fascinating story actually.<p>Some more information on <a href="http:&#x2F;&#x2F;world.time.com&#x2F;2011&#x2F;07&#x2F;07&#x2F;a-q-khans-revelations-did-pakistans-army-sell-nukes-to-north-korea&#x2F;" rel="nofollow">http:&#x2F;&#x2F;world.time.com&#x2F;2011&#x2F;07&#x2F;07&#x2F;a-q-khans-revelations-did-p...</a> and <a href="https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Abdul_Qadeer_Khan" rel="nofollow">https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Abdul_Qadeer_Khan</a><p>I did also see a very good documentary about this, but I can not find it online right now.<p>Edit: Here is the BBC documentary about Khans dealings in nuclear secrets: <a href="http:&#x2F;&#x2F;www.unewstv.com&#x2F;6821&#x2F;bbc-documentary-on-dr-abdul-qadeer-khan-pakistan-nuclear-secrets" rel="nofollow">http:&#x2F;&#x2F;www.unewstv.com&#x2F;6821&#x2F;bbc-documentary-on-dr-abdul-qade...</a> . Stranger then fiction, it has a plot like a top thriller movie.