The global environmental crisis, encompassing runaway climate change, collapsing biodiversity and the slow death of the world’s oceans, has exposed the limitations of traditional political realism as a guide to statecraft in the 21st century. The time has come for the nations of the world to embrace a new approach to world politics that treats the preservation of the biosphere as a core national interest and a central objective of national security policy. Call this new mindset ecological realism.
Political realism, which has long dominated the teaching and practice of foreign policy, including in the United States, is a venerable intellectual tradition with roots in the writings of Thucydides, Machiavelli, Hobbes and Rousseau. As formalized by mid-20th-century thinkers like Reinhold Niebuhr and Hans Morgenthau, and later by Kenneth Waltz and Robert Gilpin, among others, it depicts the international system as an inherently anarchic realm populated by independent states recognizing no superior authority. Its outlook is tragic. Inhabiting a cutthroat, self-help system in which the possibility of war is ever-present, states must remain vigilant, seeking to amass and maintain military capabilities to deter and defeat potential adversaries.
These competitive dynamics create a well-known security dilemma, whereby one state’s quest for military dominance—and its technological and economic foundations—generates anxiety among other states, which double down on their own efforts. International institutions may temporarily dampen these conflict dynamics, political realists allow, but any international cooperation is inherently fragile and transitory, because what preoccupies states is not whether they reap absolute gains from collective action, but whether they benefit more relative to others. Political realists acknowledge the utility of alliances, but they are skeptical that solidarity based on shared purposes or identities can long endure in the absence of a common adversary. International law, likewise, carries weight only when it reflects the interests of the powerful.