Opened for signature in 2017, the Treaty for the Prohibition of Nuclear Weapons (TPNW) recently reached an historic milestone when Honduras became the 50th country to ratify the Multilateral Treaty that prohibits its signatures from developing, using and threatening to use nuclear weapons. In effect, the Treaty “bans” its signatory states from possessing nuclear weapons. But what about those states which possess massive nuclear arsenals that have not signed on, including Russia and the U.S.? This show is an introduction to the Treaty which does not take effect until 2021. We focus on some International Law basics, the language of the preamble, and other legal instruments aimed at nuclear non-proliferation.