NATO's current security doctrine needs to change. It needs to enhance its political will and institutional capacity to manage climate change threats, both within the alliance itself and within the area most vulnerable to its southern flank: the Middle East. NATO will need to evolve into a CATO, a Climate Alliance Treaty Organization, that deals with the security implications of potential tipping points and develops policies in response. A case study as to how NATO can assume this role can be seen in how the organization dealt with environmental issues in Iraq, in the aftermath of war with the Islamic State.