Technology has been long understood to play a central role in limiting the proliferation of nuclear weapons. Over the last thirty years, however, systematic improvements in information, design, modeling, and manufacturing tools have eased that challenge. Could developing countries, or even small engineering firms, soon make nuclear weapons on their own? There is evidence that this transition has already occurred. This talk examines routes to the bomb that require only technologies already within reach of nearly any country without foreign assistance or access to export-controlled equipment or materials. It reports on a study of twenty historical nuclear programs, technical analyses, and reviews supporting evidence from previously secret experiments carried out by the United States and United Kingdom. If the conditions for the clandestine and indigenous production of weapons has now emerged, then nonproliferation institutions that aim to prevent the spread of weapons by controlling technology are already out of date. Although it would represent a near-foundational shift for policy, the technology landscape may now require politicians focus on the motivations behind nuclear proliferation rather than merely work to restrict access to technology.