Deterrence is the central organizing concept of current U.S. strategy. In its simplest form, the term means discouraging aggression by threatening unacceptable consequences. Countries have been practicing deterrence since the dawn of history, but the idea took on much greater importance once the appearance of nuclear weapons raised doubts about the practicality of active defense. When only a handful of weapons can cause unprecedented destruction, and both sides have such weapons, leaders tend to focus more on how to avoid wars and less on how to win them. Thus it was that deterrence became a core concern of American policymakers after Russia began building up its nuclear arsenal in the 1950s.
Initially, deterrence was focused mainly on the nuclear threat. Over time, though, military planners began to apply it to other types of aggression. Today, it can be found in official pronouncements about everything from China's territorial ambitions to global terrorism to cybersecurity. But even as deterrence has come to pervade every facet of U.S. strategy, its relevance and reliability have begun to wane. As the respected strategist Richard K. Betts observed in a Foreign Affairs essay last year, "Deterrence isn't what it used to be." Betts went on to note that it may not be feasible to deter some types of aggression and aggressors, and that policymakers often misunderstand how deterrence works anyway.
I have a more basic concern that has haunted me ever since I began studying strategy at Georgetown University during the Vietnam era. My concern is that much of the time deterrence is an illusion -- that we can never know for sure what our adversaries are perceiving or planning, and thus that the foundation for our security in the modern world is deeply suspect. From that pessimistic perspective, the question "What if deterrence doesn't work anymore?" might be followed by the query, "What if it never did?" Betts doesn't go that far, asserting that deterrence "was the essential military strategy behind containing the Soviet Union and a crucial ingredient in winning the Cold War without fighting World War III."
Most students of strategy share that view. Even if it is valid though, the world has changed. Extremists of every stripe have been empowered by new technology, and we often don't understand how they think. The intelligence community's failure to anticipate the success of ISIS insurgents in Syria and Iraq is just the latest indication of how little we know about the emerging threat landscape. Unfortunately, effective deterrence requires a fairly precise grasp of adversary values, intentions and thought processes. 9-11 and subsequent events suggest that deterrence may no longer be as useful as (we once thought) it was. Here are five worrisome ways in which circumstances are conspiring to undermine the value of deterrence in national strategy.
1. Fewer enemies fit the "rational actor" model. When deterrence theory was first systematized by economists and mathematicians at places like the RAND Corporation in the early Cold War period, they began with the assumption that adversaries were rational. There wasn't an alternative: nobody knows how to model idiosyncratic craziness. But some of the potential aggressors that we worry about today, like ISIS and Kim Jong-un, don't seem to meet a Western standard for sane behavior. Maybe they are rational within their own frame of reference, but not within ours. And even for quasi-Western, presumably sane leaders like Vladimir Putin, wartime stress has a way of changing thought processes. Deterrence might work with irrational adversaries, but not for reasons we can confidently predict or shape.
Can these fellows be deterred? Maybe not. (Image: Wikipedia)
2. Deterrence requires information we often don't have. The U.S. intelligence community does not have a good track record when it comes to anticipating threats. From Pearl Harbor to North Korea's invasion of the South to the Cuban Missile Crisis to the Tet Offensive to Iraq's invasion of Kuwait to the 9-11 attacks, intelligence agencies always seem to be playing catch-up. That is a clear sign that we seldom understand the thought processes of potential aggressors. If you can't even predict when one country is going to invade another, how likely is it that you have the fine-grained grasp of their thinking needed to deter unwanted actions? Washington's interactions with Saddam Hussein are a chronicle of continuous mis-perception on both sides, and chances are U.S. intelligence understood him a lot better than, say, the Taliban. With so little insight into adversaries, deterrence probably can't work.
3. Elusive adversaries are hard to hold at risk. Deterrence is all about retaliation, or at least the threat of retaliation. It's the fear of horrible consequences that dissuades a potential aggressor from acting in the first place. But when it takes ten years to find the mastermind of the 9-11 conspiracy, accountability becomes tenuous. Many of the non-traditional adversaries who threaten America today lack a fixed address that can be targeted in retribution. That doesn't just apply to terrorists and insurgents who "move amongst the people as a fish swims in the sea" (to quote Mao Zedong), it also applies to hackers who invade our networks and traffickers in technologies of mass destruction. The most sophisticated hacks may originate in places like China, but if they arrive via the Chicago municipal healthcare system's information network and we can't identify their ultimate authors, how can we deter them?
4. We won't know whether deterrence is working until it fails. The great philosopher of science Karl Popper insisted that scientific theories can't be proven, they can only be falsified. The same is true of deterrence. It is a psychological phenomenon that depends on the way in which enemies perceive and process information. Until we learn how to read their minds, we can't say for sure whether they are deterred. Much of what they do or say may be calculated to mislead us as to their actual intentions. And in the case of organizations like Al Qaeda, we are dealing with the proverbial hydra-headed monster rather than a unitary actor, so what one leader says and does offers little insight into the actions of others. Because deterrence is a psychological process, we cannot follow Ronald Reagan's dictum to "trust but verify" -- we can only speculate as to the meaning of behavior that often is ambiguous.
5. Effective deterrence requires more resolve than Washington exhibits. Under a doctrine known as extended deterrence, the United States provides security guarantees to a wide array of foreign nations. The credibility of these guarantees depends not only on the military capabilities that Washington possesses, but on its perceived willingness to employ them. However, international media have been awash in recent months with stories of what the Economist calls the Obama Administration's timidity. This reluctance to use military force extends beyond the White House to Capitol Hill and the broader political culture. The U.S. electorate does not want to get involved militarily in places like Syria or the Ukraine, and as David Sanger observed in the New York Times, "adversaries read polls." Sustaining deterrence when the whole world suspects you aren't willing to act sounds like Mission Impossible.
Current U.S. strategy relies too heavily on deterrence, at a time when its workability is increasingly doubtful in coping with emerging adversaries. It has become an excuse for inaction even in dealing with enemies who can be crushed using more traditional concepts of defense. Rather than waiting for the next time deterrence fails, as it inevitably will, Washington needs to think in more concrete ways about how to protect the nation against the military threats it faces. In some cases, that may mean abandoning commitments that are too dangerous or demanding. In other cases, it will mean replacing threats of retaliation with real defenses. But continuing to rely on a strategic concept that cannot be effectively implemented or verified in many cases is a prescription for disaster.
