In early 2014, violent street protests in Kyiv forced the resignation of the pro-Russian Ukrainian president Viktor Yanukovych. Within four months, Russia had annexed Crimea and was backing separatists in the eastern Donbas region of Ukraine.Ultranationalist protest groups — instrumental in the toppling of Yanukovych government — transformed overnight into volunteer battalions like Right Sector and Azov, then rushed to the eastern front, where they were lauded as patriots for undertaking the heavy fighting while the under-resourced Ukrainian state military scrambled to mobilize. Azov in particular has leveraged its social capital by integrating into the Ukrainian National Guard, where it...