This chapter adopts Bernard Miller’s model for understanding United States (US) grand strategy in the post-9/11 security environment. The September 9/11 attack ushered in a new direction for US grand strategy by challenging the Bush administration’s seemingly complacent view of threats in the international environment. The use of drones as a counterterrorism instrument of statecraft under Bush came at a high price for US soft power proclivities. Defensive realism presupposes that US power is in a decline and advocates a multilateral approach for dealing with international security threats. Since the US emerged as the sole superpower following the end of the Cold War, successive US presidents have sought to formulate a clear and consistent grand strategy in the absence of a peer competitor. Neo-conservatism had been a prominent part of the US domestic debate on foreign policy since the end of the Cold War and had a broader intellectual history stretching back at least to the 1960s.