This clear and concise text introduces four key theoretical frameworks that form the foundation of international relations--realism, liberalism, constructivism, and feminist theory--and uses levels of analysis as the primary unifying force to explain contemporary global politics. Cases on climate change; gender, peace, and security; migration; and the rise of China illustrate Kaufman's approach. The third edition explains core issues in international relations, such as the interaction of nations in a globalized world; the growing threat posed by non-state actors and civil conflicts; and the need for countries to work together to counter what have been called "existential crises," such as climate change, which threaten human lives and the planet. Significant revisions focus on discussion of democratic backsliding, the Covid-19 pandemic, cyberterrorism and cyberwar, changes to the European Union, and expanded coverage of international political economy.