Blog

By John K. Warden

Last month, the CSIS Defense and National Security Group, led by Clark Murdock and Jessica Yeats, released a new report dedicated exclusively to extended deterrence and assurance.  The report, entitled "Exploring the Nuclear Posture Implications of Extended Deterrence and Assurance," aims to identify the characteristics of the U.S. nuclear force posture that support extended deterrence and generate a strategy for maintaining assurance going forward.  The report begins by exploring extended deterrence and assurance at the conceptual level and then more specifically analyzes the competing needs and interests of U.S. allies in Europe, Northeast Asia and the Middle East.

Throughout the report, differences between extended deterrence and assurance are indentified.  For example, the difference between how allies and adversaries follow U.S. capabilities:

In contrast to potential adversaries who follow U.S. nuclear posture issues closely and with considerable expertise, U.S. allies’ defense planners may rely on less credible intelligence sources…and have more limited analytic resources for assessing the deterrence effects from changes in force structure…This explains why assurance requirements, at least in the near-term, can exceed the requirements of deterring the ally’s potential aggressor…allies can be more sensitive to certain force structure attributes and less sensitive (than their potential aggressor) to others. For example, ‘symbols’ of deterrence can be important to the credibility of assurance even if they do not affect an adversary’s deterrence calculations.