Deterrence

Deterrence means trying to stop a potential enemy from attacking by threatening to retaliate.  In theory, by building a nuclear weapons arsenal (or developing other weapons of mass destruction), a state prevents a perceived enemy from attacking it. An enemy would judge that the cost of an attack, particularly nuclear retaliation, would be greater than the potential gains.

Since the Soviet Union (now, Russia) and China acquired nuclear weapons in 1949 and 1964, respectively, the United States has relied on deterrence to discourage these countries from using nuclear weapons against it. The United States renewed its commitment to deterrence in the Joint Chiefs of Staff draft  "Doctrine for Joint Nuclear Operations" (March 2005) and the "National Military Strategy to Combat Weapons of Mass Destruction" (February 2006). The Soviet Union (then Russia) and China adopted this deterrence strategy against each other and against the United States, as have all other nuclear states with respect to their nuclear adversaries.

In the area of chemical and biological weapons (CBW), the best-known example of mutual deterrence occurred during World War II, when it appears that the threat of retaliatory use of CBW by the Allies dissuaded Germany from using these armaments. Other factors also played a role, however, such as the legal prohibition on CBW use enshrined in the 1925 Geneva Protocol, and the lack of military planning for CBW operations. In the nuclear realm, scholars often point to the absence of nuclear war between nations that hold weapons of mass destruction as proof that deterrence is viable. However, many analysts question the importance and usefulness of deterrence as a part of national security strategy, especially due to the increasing (and unpredictable) threat of terrorism.

Analysts and military officials have also raised the issue of whether missile defense could lead to a destabilizing effect on mutual deterrence. If one country's missile defense system is built up significantly, this detracts from the ability of another country's nuclear arsenal to penetrate those defenses easily. This decreased ability could lead the other country to perceive a need for a larger, more extensive arsenal, thus leading to a destabilizing effect. The argument in favor of missile defense posits that certain countries (such as North Korea and Iran) and non-state actors might have less fear of retaliation, rendering the idea of deterrence useless. In this case, the advantage of having a missile defense system may outweigh the risks.

Further Reading:

	Atomic Archive, Robert S. McNamara, Mutual Deterrence Speech
	Reykjavik Revisited, James E. Goodby and Sidney D. Drell, "Rethinking Nuclear Deterrence"
	Chairman of the Joint Chiefs of Staff, "National Military Strategy to Combat Weapons of Mass Destruction" (2/13/06)
	CRS, Amy Woolf, "Nuclear Weapons in U.S. National Security Policy: Past, Present, and Prospects"
	U.S. Joint Chiefs of Staff, Doctrine for Joint Nuclear Operations
	Baker Spring, The Implications of the Nuclear Posture Review for Extended Deterrence (Statement)
	Strategic Insights, David S. Yost, "Introduction: Special Issue on NATO and Deterrence"
	Nonproliferation Review, Ward Wilson, "The Myth of Nuclear Deterrence"
	Multimedia:
	Robert Gates, "21st Century Nuclear Weapons and Deterrence" (Video)
	Carnegie Endowment for International Peace, Michael Gerson, Jeffrey Lewis, James M. Acton, "Rethinking U.S. Nuclear Posture" (Video/Audio)
	Ward Wilson, "The Myth of Nuclear Deterrence" (Video)
	The Hoover Institution, Mark Helprin, "Rediscovering Deterrence"