article_snippet: I don't think people truly understand just how many of these weapons there are in the world,' said Rachel Bronson, executive director of the Bulletin, who publishes the notebook. '
article_snippet: Data for the US on the interactive map has been compiled using declassified documents from the US government, many of which were obtained using Freedom of Information requests.
article_snippet: declassified documents from the US government, many of which were obtained using Freedom of Information requests combined this with figures from congressional hearings, specialty magazines, and confidential sources. '
article_snippet: Creating estimates for other nuclear-armed states can be more challenging because not all provide as much information as the United States,' the authors write.
article_snippet: For instance, Britain and France have published some information about Britain and France arsenals, but much is still unavailable.
article_snippet: For Russia and the remaining nuclear-armed, estimates rely on information from Western intelligence organisations, expert studies, news media reports, and satellite imagery.
highlights_snippet: It reveals stockpile changes  in the US, UK, Russia, France, China, India, Pakistan, Israel, and North Korea .
  