Signaling has always been a favorite strategy of policymakers attempting to send messages to adversaries and allies alike. The value of signaling was highlighted particularly well by noted economist and deterrence theoretician Thomas Schelling. In The Strategy of Conflict, he argued that sending costly signals could assist policymakers in credibly indicating their intentions to other states. Talk is cheap, after all, but concrete actions that are expensive, resource intensive, and limit a state’s freedom of action are not so easy to walk back. Thus, these kinds of costly actions are viewed by many as the best way to convincingly signal intentions, mitigating credibility problems and effectively demonstrating resolve. This is why, for example, the U.S. stationed a small detachment of soldiers in West Berlin throughout the Cold War. American leaders knew that these soldiers wouldn’t stand a chance against a Warsaw Pact invasion, but they signaled the U.S. commitment to German (and, by extension, NATO) security. In other words, the soldiers acted as a tripwire, as their deaths would force American escalation and mobilize the American public for war. This tripwire ensured that the U.S. would honor its pledge to collective defense as articulated in Article 5 of the Washington Treaty, and thus American deployments in West Berlin were a kind of costly signal of resolve.
Clearly, signaling can be an immensely useful tool in a policymaker’s arsenal. By allowing states to more credibly communicate, signaling can work to minimize the risks of miscalculation and inadvertent escalation. However, signaling can frequently create many of the same problems it seeks to redress. For example, consider the recent use of the MOAB by American forces in Afghanistan. Many argued that the use of this enormous ordinance was primarily intended as a signal to North Korean leader Kim Jong-Un. But this is a problem, because frankly, nobody knows with certainty what the point of the bomb was. Perhaps it was used because regional commanders viewed it as the best tool to get the job done. If this were the case, then it would mean that North Korea played no role in the calculation to drop the bomb. Unless the Trump administration clearly articulates the exact purpose of the weapon deployment, though, it’s impossible to know with certainty what the intended message was. This lack of clarity risks creating the same confusion and credibility problems that costly signals are designed to avoid. And as Van Jackson recently pointed out at War on the Rocks, this kind of bungled signaling significantly raises the risk of war by indicating that Trump might potentially order a preemptive strike on the regime. If Kim comes to believe that a U.S. attack is inevitable, he might strike first to gain an offensive advantage. This could lead to a dangerous escalatory cycle that would precipitate an entirely avoidable conflict.
Many of these same issues emerge when one considers the deployment of Trump’s carrier “armada” to the Korean Peninsula. The U.S. regularly conducts large-scale naval maneuvers near the D.P.R.K., so North Korean policymakers might have viewed Trump’s escalation as nothing more than a continuation of status quo American policy in the area. The message was further muddied by the fact that Trump lied about the location of the Vinson Strike Group. Despite Trump claiming that the Vinson CSG was steaming toward the Korean Peninsula, it was later revealed to be near the coast of Australia. The reason for this confusion was later cleared up by the U.S. Navy: Carrier aviators on the Vinson were requalifying for carrier operations so that they would be ready to deploy as soon as they arrived in their area of operations. Despite this later clarification, there was immense confusion for days. Was Trump bluffing? Was he an idiot? Were his commanders misleading him? Nobody knew what was going on, and the situation was therefore only further complicated. In this case, just like in the case of the MOAB, the intended signal was undermined by the lack of clarity. Thus, instead of more clearly and credibly signaling American strength and resolve, the incident created many of the problems costly signals are intended to avoid.
To be clear, signaling is often an effective and important tool in international relations. The problems highlighted above do not discredit the value of costly signals in demonstrating resolve and reminding adversaries of U.S. capabilities. However, if signals are to be correctly received and interpreted, there must be far less ambiguity than what we have so far witnessed under the Trump administration.