Six reasons the Pentagon should retire ‘deterrence by denial’
The recent decade has exposed the concept’s weaknesses.
As the United States begins another presidential campaign season and conditions worsen in China, Russia, and Iran, this is a good time to step back and reconsider some of the conventional wisdom undergirding U.S. defense policy. Perhaps most flawed and underexamined is the concept of deterrence by denial.
The idea, which gained favor after the Cold War, still enjoys the loud support of defense officials, think-tank studies, and government strategies. But events of the past decade suggest their faith is misplaced. Russia was not deterred by risks of denial or punishment before invading Ukraine; China continues to reshape the security environment of the South and East China Seas through largely uncontested “gray-zone” activities; and the Pentagon’s own wargames suggest completely denying an invasion of Taiwan is likely infeasible.
Even the Defense Department’s own recent behavior underscores the growing insolvency of deterrence by denial. A flurry of diplomatic successes in the last two years strengthened alliances and improved U.S. defense posture in Australia, the Philippines, Japan, and Vietnam. At the same time, the proposed U.S. defense budget reduced spending in real terms, with each of the U.S. military services accepting troop cuts to pay for future high-tech weaponry. Far from a “ring of steel” around allies like Taiwan, these developments suggest the DOD is pursuing a more sophisticated strategy to convince China’s leaders that aggression is risky and could cost more than it gains.
Here are six reasons why deterrence by denial no longer works as an organizing construct for U.S. strategy:
It is vague. On its face, “denial” implies U.S. and allied forces will stop or reverse the efforts of aggressors, as they did against Iraq during Operation Desert Storm. That may not be possible if, for example, China—a nation of 1.4 billion with the world’s largest navy, coast guard, shipping fleet, and rocket force—invades Taiwan, a nation of 24 million with a modest military. Confronted with the concept’s infeasibility, advocates often argue that “denial” means creating uncertainty for the aggressor, which is opposite of the certainty a denial strategy should convey. And uncertainty is likely better achieved by making the U.S. military more creative and resilient rather than dramatically and unaffordably expanding its capacity for predictable strike operations.
It is aimed at the wrong audience. If its goal is actually to shake the potential aggressor’s confidence and reshape its risk calculus, the DoD should pursue capabilities, tactics, and posture that maximize uncertainty based on assessments from the U.S. intelligence community about opponents’ concerns. However, in practice DoD budgets are designed to convince U.S. defense officials and Congress that U.S. and allied forces could deny aggression because that is easier to explain.
It distorts U.S. force design. Rendering strategy into an operational analysis of what forces are needed to stop an act of aggression is satisfying and helps justify defense programs. However, a force able to sink 350 ships in 72 hours may only be a larger version of the force adversaries like China are already planning against and the resulting increase in uncertainty will be small. Moreover, building the capacity to meet denial metrics is likely to crowd out capabilities to address other paths aggression could take, such as protracted blockades, cyber and information campaigns, or incremental attacks by paramilitaries.
It may not be feasible against new forms of aggression. A strategy of denial depends on something to deny. The rising efficacy of gray-zone operations and potency of cyber and information warfare suggests different approaches are needed to deter an opponent willing to take a slower or more circuitous path to its goals. In China’s case, this will likely require the U.S. military to engage in gray-zone confrontations and take actions that influence leaders in Beijing to steer away from escalation.
It undermines U.S. credibility. Denial demands the infliction of rapid, massive losses that could lead to catastrophic escalation against a nuclear-armed opponent. Based on the U.S. government’s reticence to provoke Russia through more robust support to Ukraine, U.S. leaders could be expected to avoid implementing a denial campaign, which weakens deterrence.
It imposes disproportionate costs on the U.S. military. Sustaining the overseas posture needed for short-notice strikes against hundreds of ships or thousands of vehicles is expensive and challenging for a military already at the breaking point. Exacerbating this problem, it is cheaper for an opponent like China to field targets than it is for the current U.S. military to field effective shots on target.
The time has come to retire deterrence by denial. It had a good run when the U.S. was dominant, but denial no longer means what it says and drives U.S. defense plans and investments toward greater predictability rather than creating uncertainty for opponents. In denial’s place, DoD leaders should more fully embrace the approach implied by their 2022 National Defense Strategy. Its lines of effort for Integrated Deterrence, Campaigning, and Building Enduring Advantages are focused more on targeting adversaries’ vulnerabilities and undermining their confidence than perpetuating denial as a basis for defense planning.
The Pentagon’s recent successes in the Indo-Pacific reflect Integrated Deterrence in action. But episodic victories like these will not by themselves keep adversaries off-balance and unwilling to act. They should be complemented by a long-term campaign, guided by rapidly improving information technologies, that shows how constantly-evolving U.S. and allied capabilities could defeat aggressors’ strategies and enable defenders to prolong a fight like Ukraine is doing to Russia. A recent Hudson Institute report outlined this approach and the technologies and concepts that could bring it to life.
The first step toward change is admitting there is a problem. The 2022 National Defense Strategy started down this path by de-emphasizing denial. But easy ideas are hard to abandon. Pentagon leaders need to do the hard work to describe and implement approaches that will create uncertainty and costs for potential aggressors like China while conflict can still be averted.
Bryan Clark is a Senior Fellow at the Hudson Institute and Director of the Hudson Center for Defense Concepts and Technology. Dan Patt is a Senior Fellow at the Hudson Institute.