The nexus of climate change, human mobility, and instability demands new forms of multilateral engagement and an end to the outdated divisions of labor within governments. However, bureaucratic inertia is strong, and there is often an inadequate understanding of the urgency of this far-reaching transformation among political and military leaders; many still try to make sense of the world through the dated perspectives of the past century. In the 21st century, security needs to be defined more broadly – complex crisis scenarios revolve around the ability to compel collective action to address fundamental transnational problems. Mobilizing this sort of action to address the nexus between climate change, human migration, and instability will be the political litmus test of our time.