As Ukraine continues to fight against Russia's invasion of their country and continues to attack Russian territory, concerns persist that Russia could resort to using nuclear weapons (AP, US News & World Report). Russian and Belarusian territory and airspace include that within the boundaries generally recognized by the international community, including territorial waters. For the purposes of this question, a "nuclear device" is one that is designed to produce a nuclear explosion utilizing the fission and/or fusion of nuclear fuel (e.g., Uranium-235, lithium deuteride). A radiological device (aka "dirty bomb") would not count (Nuclear Regulatory Commission). A device that produces an explosive detonation for a sub-critical test is not considered a "nuclear device" that is designed to produce a nuclear explosion. Confused? Check our FAQ or ask us for help. To learn more about Good Judgment and Superforecasting, click here. To learn more about how you can become a Superforecaster, see here. For other posts from our Insights blog, click here.