Russian actions in Ukraine in 2014 have prompted an urgent reassessment of the defense posture of many European nations. The Nordic states in particular are grappling with a 2-decade legacy of defense drawdowns and repositioning for expeditionary warfare. The challenge for these nations is how to resurrect a credible military deterrent in the face of continuing Russian assertiveness. One attractive option is closer defense cooperation between the Nordic states, but moves in this direction are slow and faltering. Political complications include the deeply ambivalent attitude of Sweden and Finland to the prospect of NATO membership. In this monograph, two leading Nordic defense experts assess the progress of cooperation to date, both within the region and externally with the United States, and offer specific recommendations for urgently enhancing both.