What role does NATO play in combating terror? NATO's missions have expanded dramatically since the end of the Cold War, and most of the United States’ closest allies are members of the alliance. Nevertheless, NATO plays, at best, a supportive role in U.S. efforts to combat terrorism. The alliance contributes to preventive and defensive missions to address the threat of terrorism, and its consequence management plans aim to respond to terrorist attacks and to mitigate their effects. But many of the essential activities of the fight against terrorism occur outside NATO, through bilateral cooperation or loose coalitions of the willing. Three factors help to explain NATO's minor role in combating terrorism: shifts in alignments and threat perceptions caused by systemic changes, the alliance's limited military capabilities, and the nature of the fight against terror itself. Over time the consequences of NATO's limited role could be severe. If NATO's strongest members do not seek to address their core security threats within the alliance, NATO may have difficulty sustaining its military value.