This chapter highlights weapons-systems as a central aspect of the question: ‘Security how?’ Weapons are a central and pervasive aspect of the material, institutional, and discursive mobilizations of security. As such, weapons have long been both a tool and a measure of power. Weapons-politics reveals what we might think of as lethal legitimations: the legitimation of killing, the preparation for killing, and the distinctions (racial, colonial, gendered, religious, class, civilizational) that allow us to take for granted that killing is inherent to security. The chapter poses three questions about security and violence that arise through weapons-politics: Does the manner of violence matter? How are weapons controlled? How is weapons-politics entangled with other forms of violence and security? These questions show that weapons-systems are the materialization of violence of all types.