Contrary to predictions by many experts, Ukraine’s military has been resilient in the face of the Russian government’s invasion. Drawing on the logic of polycentric defense, this paper helps explain how Ukraine has remained resistant against a conventionally more powerful adversary. We argue...

Why does liberal democracy take hold in some countries but not in others? Why do we observe such different outcomes in military interventions, from Germany and Japan to Afghanistan and Iraq? Do efforts to export democracy help as much as they hurt? These are some of the most enduring questions...