In the 60&#x27;s the government enlisted two fresh physics PHDs to see if they could design a plausible bomb, as a stand in a random country. In they end they succeeded in creating a detailed plan, and it didn&#x27;t even take them that long.<p>There&#x27;s much more public info out there now, and machining has improved significantly in the past 50 years, so the main barrier to building a crude bomb is material rather than the expertise or machining.<p><a href="http:&#x2F;&#x2F;www.theguardian.com&#x2F;world&#x2F;2003&#x2F;jun&#x2F;24&#x2F;usa.science" rel="nofollow">http:&#x2F;&#x2F;www.theguardian.com&#x2F;world&#x2F;2003&#x2F;jun&#x2F;24&#x2F;usa.science</a>