The humanitarian principles, and more precisely their interpretation, are not only instructive in understanding humanitarianism and the humanitarian identity(ies), but they are also consequential for the security and the security approaches of humanitarian NGOs (Renouf 2011) and the ways in which NGOs deal with security issues might also affect their identity. In this chapter, I will first elaborate on the NGOs’ reactions to insecurity in terms of security approaches. Second, I will present how humanitarian NGOs are changing their internal security management before I will show that they are also increasingly establishing inter-organizational security cooperation networks. However, the literature on humanitarian NGOs and on cooperation between organizations would rather lead us to assume that humanitarian NGOs refrain from institutional changes and cooperation with respect to security. In the last section of this chapter I will therefore discuss the relevant theoretical arguments.