Forum: Painful consequences for Iran

John Bolton, U.S. ambassador to the United Nations and president of the U.N. Security Council, warned Iran of "tangible and painful consequences" in an effort to deter Tehran from its nuclear activities and its threat to accelerate its enrichment program toward large-scale production.

With the U.S. entangled in Iraq, are threats of this type now wholly credible? That depends on how effectively the United States deters activities contrary to its interests. Deterrence relies on explicit and implicit threats to create cause a would-be adversary to fear to pursue an undesirable course of action. Failure could lead to military action and, in extremis, to the unthinkable: a horrific nuclear strike.

During the Cold War, deterrence was thought of in terms of nuclear weapons. The two former superpowers threatened nuclear retaliation in response to strategic aggression, which would ultimately lead to certain Armageddon. This balance of terror resulted in a kind of strategic stability that kept an uneasy peace for more than 40 years. This kind of "strategic" deterrence is still needed to deter potential adversaries with large nuclear arsenals. However, there is a growing recognition that the security threats of today -- and the future -- demand a much broader approach. The Defense Department refers to this as "tailored deterrence" in its 2006 strategy document, the Quadrennial Defense Review (QDR).

It has long been known that actual use of nuclear weapons would represent the ultimate failure of deterrence. But this underscores an important conundrum: If anyone -- adversaries and allies alike -- doubts that these weapons could be used, the likelihood they would be used increases. This is why perceptions of U.S. self-deterrence are particularly dangerous.

As the logic goes, the political and ethical consequences of using nuclear weapons make timely and necessary action prohibitive except in the most dire circumstances. The question then is how to strengthen the credibility and resolve underpinning our deterrents below the nuclear threshold.

This presents unique difficulties when dealing with new and emerging challenges, such as those posed by al Qaeda and states with nuclear ambitions. At present, the only way we can "hit" time sensitive targets is to use a nuclear missile -- it's the only capability in the U.S. arsenal fast enough to reach anywhere on the globe within an hour. For example, the U.S. might want to target the leadership of a terrorist group located by intelligence agencies -- intelligence hard-won and only usable for several hours. But the U.S. would likely want to do so without using a nuclear weapon. Such gaps must be addressed.

The QDR seeks to address these gaps: The Defense Department introduced the idea of equipping existing submarine-launched Trident ballistic missiles with conventional warheads. The president's 2007 budget, currently making its way through Congress, seeks funding for feasibility and development studies. Such weapons could offer the president the ability to strike anywhere globally within an hour -- a capability now only achievable by nuclear weapons and unlikely through other technologies, such as hypersonic cruise missiles, for 10 years or more.

Critics of this proposal are worried that this weapon, if used, could be misinterpreted by an adversary or third party as a nuclear strike. If such a country is nuclear armed, this could lead to a catastrophic result for the United States.

However, it is possible to work around this obstacle; the communication channels used to inform other states of U.S. ballistic missile tests can be adapted to eliminate this risk.

Another criticism is that the proposal would blur the distinction between the nuclear role of ballistic missile submarines and conventional war fighting forces -- leading to a reduced nuclear threshold and making nuclear weapons more usable.

But the nuclear taboo remains a powerful disincentive. No sane politician wishes to use nuclear weapons and would only do so as a last resort in extreme circumstances.

When looking at the unfolding situation in Iran, it is clear a broader spectrum of capabilities is required to underpin U.S. and allied deterrence capabilities.

A conventional Trident option should be one such tool in the political, economic and military toolkit. With this in mind, the innovative new Defense proposal should be funded through to deployment to allow the United States to -- when necessary -- make credible, "tangible and painful" and explicit threats, in place of implicit threats that may lack credibility today.

KATHLEEN MCINNIS and OWEN PRICE

Kathleen McInnis is coordinator of the Project on Nuclear Issues at the Center for Strategic and International Studies. Owen Price is a visiting fellow in residence at the project. The views expressed are their own.