The Burden-Sharing Dilemma examines the conditions under which the United States is willing and able to pressure its allies to assume more responsibility for their own defense. The United States has a mixed track record of encouraging allied burden-sharing—while it has succeeded or failed in some cases, it has declined to do so at all in others. This variation, Brian D. Blankenship argues, is because the United States tailors its burden-sharing pressure in accordance with two competing priorities: conserving its own resources and preserving influence in its alliances. Although...