Scott Sagan wrote a typically fine essay in the Spring 2000 issue of International Security on “The Commitment Trap.” His subject was the Bush administration’s use of “calculated ambiguity” to deter Saddam Hussein from using chemical or biological weapons in the run-up to the second Gulf war. After disavowing chemical weapons (1992) as well as biological weapons (1972), senior U.S. officials have sought to deter their use by others by issuing warnings of “absolutely overwhelming” and “devastating” responses. These code words imply the use of nuclear weapons.
Scott argued, persuasively in my view, that veiled threats to use nuclear weapons trapped U.S. officials. If CW or BW were actually used by an adversary — regardless of their scope and military effectiveness, whether from top-down dictates or breakdowns in command and control — Washington could feel impelled to carry out its threat, thereby inviting immeasurable but significant costs to its international stranding and to the Nuclear Nonproliferation Treaty. Alternatively, by refraining from carrying out its nuclear threat, Washington could also lose international standing, inviting new adversaries to call its bluff and old friends to question the protectiveness of the U.S. nuclear umbrella. To avoid these awful choices, Scott proposed that calculated ambiguity be replaced with a clear and credible U.S. commitment to respond to CW and BW use with prompt and devastating conventional retaliation.
One measure of the devaluation of nuclear weapons is the decreased utility of nuclear threats, whether blatant or veiled. Only one state currently employs blatant, crude and credible nuclear threats. By making them, Pyongyang increases its separation from states that are not in the grip of paranoia. Veiled nuclear threats have been more frequent. Along with the second Gulf war, they were made during intense crises between Pakistan and India from 1999 – 2002, but were notably absent after the 2008 crisis sparked by terrorist attacks in Mumbai. Russia, which has increased its reliance on nuclear weapons, has no reason to threaten their use, making any public statement along these lines to seem strangely atavistic. Major Powers in possession of nuclear weapons lose rather than gain standing by making veiled nuclear threats against weaker states.
The commitment trap that Scott wrote about two decades ago has changed significantly. As before, the trap is set by drawing red lines and making assertions that certain actions are “unacceptable.” What’s different is that these public statements are prompted not only to deter actions – currently by Syria and Iran — but also to delay or prevent actions by a friendly state, Israel. Another big difference is that the commitment trap is no longer about the veiled threat of using nuclear weapons. Nor is Scott’s proposed remedy — prompt and devastating use of conventional capabilities – a likely option.
The commitment trap is now about drawing red lines and then feeling obliged to back them up with selective, conventional military strikes. The prelude to U.S. air strikes in Syria could be the establishment of a no-fly zone. For some, military action is not a trap – it’s a long-postponed necessity. For the Obama administration, rhetorical devices employed to deter and to buy time are running out of time.