Extended Deterrence

President Obama meets with leaders of NATO states
Source: macedonia.usembassy.gov

The threat to retaliate against an adversary with nuclear weapons on behalf of a third-party is called extended deterrence, and is sometimes referred to as the nuclear umbrella. Through military alliances, such as the North Atlantic Treaty Organization (NATO), and other mutual defense treaties, the United States has agreed to extend its nuclear umbrella over its allies and friends. During the Cold War, the Soviet Union entered into similar arrangements with its allies.

The U.S. nuclear umbrella in particular has provided many industrially-advanced countries with the option to choose not to develop WMD, even though most are technically capable of doing so. "The National Security Strategy of the United States" (March 2006) reiterated the importance of maintaining credible nuclear forces as a deterrent against threats to the United States and its allies. This policy additionally stated that the United States' New Triad (first introduced in the 2001 Nuclear Posture Review) will "bolster security commitments" to U.S. allies, and aid nonproliferation objectives by convincing these countries not to build their own nuclear weapons programs. Extended deterrence offers one possible reason for states not to proliferate.

The U.S. administration under President Obama will be releasing a new Nuclear Posture Review to Congress in March 2010. Although the contents of the review are not yet known, analysts widely believe that the tenets of extended deterrence will be retained. This is based in part on the highly influential report submitted by the Congressional Commission on the Strategic Posture of the United States, which strongly recommends that the government continue its commitment to extended deterrence for its allies.

Further Reading:

	Strategic Insights, Special Issue on Extended Deterrence, Security Guarantees, and Nuclear Proliferation: Strategic Stability in the Gulf Region
	The Washington Quarterly, Kathleen McInnis, "Extended Deterrence: The U.S. Credibility Gap in the Middle East"
	CATO Institute, Jeffrey Record, "Nuclear Deterrence, Preventive War, and Counterproliferation"
	Arms Control Today, Masa Takubo, "The Role of Nuclear Weapons: Japan, the U.S. and 'Sole Purpose'"
	CNS, Miles Pomper, et al., Reducing and Regulating Tactical (Nonstrategic) Nuclear Weapons in Europe
	Natural Resources Defense Council, "U.S. Nuclear Weapons in Europe"
	Congressional Commission on the Strategic Posture of the United States, Final Report
	Air University, Thomas Scheber, "Contemporary Challenges for Extended Deterrence"
	Multimedia:
	Lowy Institute for International Policy, Rory Medcalf, "Could US Disarmament Spark Increase in Nuclear Weapons?" (Video)
	Carnegie Endowment for International Peace, Scott Sagan, Lukasz Kulesa, Amb. Yukio Satoh, George Perkovich, "Are the Requirements for Extended Deterrence Changing?" (Transcript or Audio)
	NPR, Mike Shuster, "Iran Prompts Debate Over Mideast Defense Umbrella" (Transcript/Audio)