• American presidents are accompanied by a military aide carrying a briefcase with the tools necessary for nuclear war.
  • During presidential inaugurations, nuclear command authority and the "nuclear football," as the briefcase is called, are transferred to the new president.
  • But President Donald Trump says he will not participate in President-elect Joe Biden's inauguration, which could complicate the transfer.
  • The Pentagon told Insider there was a plan for the transfer in that scenario but declined to provide details. Nuclear-weapons experts and a former military aide who carried the briefcase were able to offer some insight though.
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