Are only poor nations at risk?

No. A combination of exposure to climate risks, and governance deficiencies, determines whether not a nation is at risk. This includes poor, middle-income and wealthy nations. Extremely poor and unstable nations are especially at risk due to the fact that significant existing pressures will be made worse – especially stresses on food and water security. However, middle-income and wealthy countries are also susceptible to the security risks of a changing climate. For example, the nations of the Middle East and North Africa, though mostly middle-income countries, are facing declining winter precipitation as a result of climate change, which has already contributed to instability. Many of these countries are also highly dependent on wheat imports from the global food market, which is in turn very vulnerable to climate shocks. As the provision of basic services becomes less reliable, the social contract between citizen and government can rapidly erode. This can lead to instability, as well as a greater incidence of authoritarian responses. Sea level rise, and an increase in the severity and intensity of extreme weather events, can also threaten wealthy nations that have vulnerable energy, military and agriculture infrastructures, both inland and along the coasts. Cascading disasters have the potential to place such enormous strains on wealthy nations, that economies and critical infrastructure can be severely disrupted.

Read more:

2015: National Security Implications of Climate-Related Risks and a Changing Climate, U.S. Department of Defense
2014: Quadrennial Homeland Security Review (QHSR), U.S. Department of Homeland Security
2014: Heyman and Durkovich, U.S. Department of Homeland Security: “Statement for the Record, Extreme Weather Events: The Costs of Not Being Prepared, Committee on Homeland Security and Governmental Affairs, United States Senate.”
2014: Climate Change Adaptation: DOD Can Improve Infrastructure Planning and Processes to Better Account for Potential Impacts. GAO-14-446
2014: Extreme Weather Events: Limiting Federal Fiscal Exposure and Increasing the Nation’s Resilience. GAO-14-364T. (Feb 12, 2014)
2014: Climate Change and EU Security Policy: An Unmet Challenge. Youngs, R. Carnegie Europe
2013: National Intelligence Council Report: “Natural Resources in 2020, 2030, and 2040: Implications for the United States.” (July 25)
2013: Council of the European Union 2013. Council conclusions on EU Climate Diplomacy. Foreign Affairs Council meeting, Luxembourg 24
2010: Organization for Security Co-operation in Europe (OSCE): Shifting Bases, Shifting Perils: A Scoping Study on Security Implications of Climate Change in the OSCE Region and Beyond
2008: European Commission: The European Union and the Arctic Region