Rising tensions throughout the world, especially in crisis areas like Ukraine, Iraq, and Israel/Palestine, has brought the issue of conflict escalation to the forefront of political decision-making. In Donetsk and Luhansk, continuing clashes between pro-Russian rebels and the Ukrainian military in the aftermath of the downing of a civilian airliner by a surface-to-air missile raise the fear of escalation from a conventional conflict to one where the use of non-conventional weapons, including limited nuclear strikes. In addition to increasingly bellicose statements by Russian officials over Western intervention in Crimea, Russian nuclear doctrine highlights the avenues for nuclear use in such a scenario. It states, “the Russian Federation reserves the right to utilize nuclear weapons in response to the utilization of nuclear and other types of weapons of mass destruction against it and (or) its allies, and also in the event of aggression against the Russian Federation involving the use of conventional weapons when the very existence of the state is under threat.” Perhaps surprisingly, this is not the first time a Russian official has discussed the possibility of limited nuclear warfare. In 2011, General Staff Chief Gen. Nikolai Makarov warned “the possibility of local armed conflicts virtually along the entire perimeter of the border has grown dramatically. I cannot rule out that, in certain circumstances, local and regional armed conflicts could grow into a large-scale war, possibly even with nuclear weapons.” These discussions in Ukraine and other conflict areas, such as East Asia as North Korea continues to pursue increasingly aggressive rhetoric and actions against its neighbors, has motivated serious discussions in the policy and military communities about the very real possibility of the limited use, whether deliberate or as a result of unintended escalation, of nuclear weapons. This marks a significant departure from both status quo policy and public opinion about nuclear weapons use. Since the development and first, and only, uses of nuclear weapons during World War II, policy-makers and military officials have centered their attention and resources on nuclear deterrence. Yet, as crises continue to develop and raise the spectre of escalation and the use of weapons of mass destruction by state or non-state actors, they demand additional focus on key questions about limited nuclear warfare. How likely are limited nuclear strikes in response to the use of kinetic or non-kinetic weapons in other domains, such as cyber or space? Perhaps more importantly, in consideration of the huge human cost of nuclear weapons, what steps need/can be taken to ensure that a conflict that involves nuclear weapons remains limited? Understanding the new frontier of limited nuclear strikes requires in-depth understanding of the history and nuances of limited nuclear warfare, how it is likely to manifest in the 21st century with developing weapons and technology, different domains and arenas for use, and evolving nuclear doctrine among a new cadre of actors. Only then can we truly begin to comprehend the heavy toll that weapons of mass destruction is sure to take on our global community.