The legality of nuclear weapons, nuclear war, and nuclear deterrence have been much debated over the years and a 1996 Advisory Opinion of the International Court of Justice did little to settle the issue. What if the ICJ were to take up the issue again? Would the result be any different, especially in light of the negotiation of the 2017 Treaty on the Prohibition of Nuclear Weapons? Please join us for a discussion of these issues. Our speaker will be Newell Highsmith, who supervised the Arms Control and Nonproliferation section of the Legal Office at the Department of State from 2001 to 2017. He will summarize the main lines of argument and conclusions from a new monograph on the subject, produced by the Center for Global Security Research at Lawrence Livermore National Laboratory.