Freedom of Navigation Operations (FONOPS) have gained considerable attention in the press recently. After a hiatus, the U.S. Navy again began challenging China’s excessive maritime claims in the South China Sea in 2015. This renewed effort commenced with USS LASSEN’s operation at Subi Reef in the Spratly Islands on October 27, 2015 and most recently featured USS CURTIS D. WILBUR’S operation at Triton Island in the Paracel Islands on January 30, 2016. Both occurring in the South China Sea, the latter demonstrated U.S. commitment to challenging China’s excessive claims outside the Spratly Islands as well. While these operations can contribute to a larger deterrence strategy, we should not rely on FONOPS exclusively for strategic signaling.
The U.S. Navy has maintained a formal FONOPS program globally since 1979. Specifically, this program is designed to prevent excessive claims from becoming customary international law. A nation can argue that its excessive claims are in fact legal if it can show that other states have acquiesced. Customary international law, in effect, validates the negative. If no nation challenges the claim over time, it can be judged as internationally accepted. The FONOPS program prevents this outcome by sending ships through excessively claimed areas to demonstrate positive non-acquiescence. In the operations listed above, China requires foreign warships to obtain permission before entering “adjacent waters,” so LASSEN and CURTIS D. WILBUR sailed within 12nm of Subi Reef and Triton Island without China’s permission to demonstrate non-acquiescence.

USS Curtis Wilbur (DDG 54) patrols the waters of the Arabian Gulf as part of Carrier Task Force Five Zero (CTF-50) deployed in support of Operation Southern Watch.
As a Navy, presence is the foundation of our deterrence mission, but we should be careful not to conflate FONOPS presence with comprehensive deterrence. While these operations have gained more media attention than any other regional operations, Pacific Command maintains a more persistent presence through efforts such as Pacific Presence Operations and the Continuous Bomber Program. We do gain some deterrence side-effects any time that U.S. forces are present, but leaning on FONOPS as a primary deterrence option is a strategic pitfall.
Credible deterrence is composed of three elements: capability, capacity and resolve. While not a linear relationship, an adversary’s doubt in any individual element will sharply reduce deterrence effects. The error in considering FONOPS as a deterrence operation is that policymakers will expect more effects from these transits than FONOPS can offer. This mistake is particularly evident when treating FONOPS as Flexible Deterrence Options (FDOs).
When designing a deterrence strategy against an adversary, FDOs can prove useful in controlling security dilemma effects — a phenomenon where actions intended to increase one’s own security can in fact reduce it, because those actions instill fear in the adversary, which responds with similar security improvements. FDOs help control this outcome by allowing policymakers to apply the minimum show of force necessary to achieve the desired effect. Should the adversary appear unresponsive, the intensity of FDOs can be increased like a rheostat. Of the three elements of deterrence — capability, capacity and resolve — FDOs have the largest impact on resolve. The adversary has likely already calculated the capability and capacity of opposing armed forces; employing forces through more assertive FDOs signals firm resolve.
FONOPS is a fairly straightforward legal program, which is why it falls short in an FDO approach. When facing excessive maritime claims, states either demonstrate non-acquiescence or not. There is no practical difference between non-acquiesce and strenuous non-acquiescence, so these operations are far less “flexible” than some might hope. This is also true when a state asserts multiple excessive claims around the same land feature. For example, if a state requires foreign-warships to obtain permission before transiting within 12nm of an illegally drawn straight baseline, two excessive claims exist: (1) the requirement for permission and (2) an illegally drawn straight baseline. Transiting within 12nm of the straight baseline without permission demonstrates non-acquiescence against the first, but unless the straight baseline is crossed, that state can show acquiescence to the second. Reserving the second as a way to “escalate” in an FDO approach is a fool’s errand. Just as there is no practical difference between non-acquiesce and strenuous non-acquiescence, there is similarly no difference between acquiescence and reserved non-acquiescence. Altogether, you can neither non-acquiesce more nor acquiesce less.
Given these limitations, FONOPS still play an important role in strategically signaling allies and partners. In the case of the South China Sea, the United States seeks to prevent Beijing from coercing smaller regional powers into accepting its excessive claims. Thomas Schelling famously observed, “There is a difference between taking something and making someone give it to you.” To be sure, China has taken the Paracel Islands and Scarborough Shoal, but the larger strategic victory for China would be making these smaller powers accept de facto Chinese control over the South China Sea. Beijing can set the conditions for this outcome if it effectively conveys to regional neighbors that resisting Chinese excessive claims is pointless. Asserting these claims, and backing them with overwhelming and credible force such that smaller states cannot oppose them, will secure de facto control. If the U.S. Navy is not there demonstrating non-acquiescence, these states will likely be coerced into acquiescing.
This effect highlights the strategic importance of FONOPS in the South China Sea. FONOPS cannot deter China from reclaiming islands and militarizing them into bases, but these operations play an important role in signaling smaller regional states. U.S. Navy demonstrations of non-acquiescence assuage fears in these states that they are alone in opposing China’s excessive claims, assuring these governments that international rule of law takes precedence over China’s strategic aspirations. While FONOPS is not a deterrence program, these operations allay concerns that Chinese control over the South China Sea is a fait accompli.