Predicting scientific and technological development and, as a result, developing a list of critical technologies in advanced countries is quite common and systematic. Ukraine, however, forms such a list exclusively for the defense sphere. Highlighting the most promising technological directions that can be implemented in the field of weapons and military equipment requires a clear understanding of the key principles for the operation of new and advanced weapons, as well as the relevance and priority of the development of certain civilian technological areas, which may eventually move into the military. This paper provides a forecast of the development of the security situation in the world as of 2045. It identifies likely leaders who will spend more than twice as much on their defense, with only two advanced countries that are likely to be at the highest level of military power. It also noted a possible decline in Russiaʼs military capabilities, but an armed threat remains. The origin of a new sphere of military presence is described – cyberspace, which necessarily entails a change in the forms of future wars. It is also noted that the rapid development of certain technologies, which is currently undergoing scientific and technological development, can lead to catastrophic consequences for all humanity. Some of the achievements and main principles of the Fifth and Sixth Technological Units, which will inevitably be applied in the development of the latest weapons, are outlined. Possible directions of modernization of certain available types of weapons are described, as well as key indications of future military conflicts and prospective weapons. In addition, the article provides some data that is drawn from science fiction, but it is quite likely to be used in the creation of promising weapons complexes based on the latest physical principles of action.